1041-00005 · Client 1041 · Engagement & Client Management

engagement-letter-solara-plr.docx DOCUMENT M&A / Corporate

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CALDERWOOD & HARKNESS LLP Attorneys at Law

600 Lexington Avenue, 38th Floor New York, New York 10022

Telephone: (212) 554-8000 Facsimile: (212) 554-8001 www.calderwoodharkness.com

May 12, 2025

VIA EMAIL AND Sundial Data Systems

Priya Narasimhan, Esq. General Counsel Solara Digital Infrastructure LP 1200 Market Street, Suite 3400 Wilmington, Delaware 19801

Re: Engagement of Calderwood & Harkness LLP — Private Letter Ruling Request in Connection with Cross-Border Fund-Platform Reorganization of Solara Digital Infrastructure LP

Engagement Number: 20250527-SDILP-PLR

Dear Ms. Narasimhan:

1. Purpose and Acceptance

Calderwood & Harkness LLP ("Calderwood & Harkness" or the "Firm") is pleased to confirm its engagement by Solara Digital Infrastructure LP ("Solara" or "SDILP"), a Delaware limited partnership, and its general partner, Solara Digital Infrastructure GP LLC ("Solara GP"), a Delaware limited liability company (collectively, the "Client"), to provide the legal services described in this engagement letter (this "Letter"). We appreciate the confidence that Solara and Solara GP have placed in our Firm, and we look forward to working with your team on this significant and complex matter.

This Letter sets forth the terms and conditions upon which Calderwood & Harkness will provide legal services in connection with the matter described herein. By countersigning this Letter in the space provided below, the Client agrees to be bound by the terms and conditions set forth herein. This engagement shall be effective as of the date of the countersignature below. No attorney-client relationship will be deemed to have been established with respect to the matter described herein until this Letter has been signed by an authorized representative of the Client and returned to the Firm.

2. Description of the Client

The client for this engagement is Solara Digital Infrastructure LP (EIN: 82-4917366) and Solara Digital Infrastructure GP LLC (EIN: 82-4917365). For the avoidance of doubt, the "Client" as used throughout this Letter refers collectively to SDILP and Solara GP, except where the context clearly requires otherwise.

Solara is a Delaware-based private equity sponsor with approximately $14.7 billion in assets under management as of March 31, 2025, operating across digital infrastructure and enterprise SaaS verticals. Solara sponsors private equity funds through a series of parallel fund structures established across Delaware, the Cayman Islands, and Luxembourg to accommodate U.S. taxable, U.S. tax-exempt, and non-U.S. investor pools. The fund platform reflects a multi-jurisdictional architecture that is common among institutional-scale private equity sponsors and is central to the reorganization that is the subject of this engagement.

The principal contact persons at Solara for purposes of this engagement are as follows:

• Priya Narasimhan, General Counsel — primary legal contact and authorized decision-maker for engagement-related matters;

• Stefan Dalmqvist, Head of Tax — primary contact for substantive tax matters, financial data, and coordination with the Client's independent auditors and valuation advisors.

The Managing Partner and Founder of Solara is Viktor Raines. Mr. Raines will serve as the authorized officer of Solara Digital Infrastructure GP LLC for purposes of executing any penalties of perjury declarations and other representations required in connection with Internal Revenue Service ("IRS") submissions, as described more fully in Section 8 below.

All communications from the Firm regarding this engagement should be directed to Ms. Narasimhan and Mr. Dalmqvist, unless otherwise instructed in writing by the Client.

3. Scope of Engagement

3.1 Overview of the Transaction

Solara is undertaking a cross-border reorganization of its fund platform (the "Reorganization"), involving the domestication and merger of several Cayman Islands and Luxembourg fund vehicles into a newly established Delaware-domiciled master fund structure. The Reorganization is designed to simplify the Client's fund architecture, reduce administrative and operational costs, enhance investor reporting, and achieve certain tax efficiencies in connection with the ongoing management and eventual disposition of portfolio company interests.

The Reorganization involves the following existing fund vehicles (collectively, the "Legacy Fund Vehicles"):

(i) Solara Digital Partners Fund IV LP — a Delaware limited partnership with approximately $4.2 billion in committed capital (vintage 2021), approximately 72% deployed as of the date hereof;

(ii) Solara Digital Partners Fund IV-A (Cayman) LP — a Cayman Islands exempted limited partnership with approximately $1.85 billion in committed capital, operating as a parallel fund to Fund IV for U.S. tax-exempt and non-U.S. investors;

(iii) Solara Digital Partners Fund IV-B (Luxembourg) SCSp — a Luxembourg special limited partnership (société en commandite spéciale) with approximately €1.15 billion in committed capital (approximately $1.24 billion at an assumed exchange rate of 1.08 EUR/USD), operating as a parallel fund to Fund IV for certain European institutional investors;

(iv) Solara Digital Partners Fund V LP — a Delaware limited partnership with approximately $5.6 billion in committed capital (vintage 2023), approximately 38% deployed as of the date hereof;

(v) Solara Digital Partners Fund V-A (Cayman) LP — a Cayman Islands exempted limited partnership with approximately $2.45 billion in committed capital, operating as a parallel fund to Fund V for U.S. tax-exempt and non-U.S. investors; and

(vi) Solara Digital Partners Fund V-B (Luxembourg) SCSp — a Luxembourg special limited partnership (société en commandite spéciale) with approximately €1.38 billion in committed capital (approximately $1.49 billion at an assumed exchange rate of 1.08 EUR/USD), operating as a parallel fund to Fund V for certain European institutional investors.

The Reorganization contemplates the formation of the following new entities (collectively, the "New Fund Vehicles"):

(i) Solara Consolidated Master Fund LP — a Delaware limited partnership to serve as the master fund in a restructured master-feeder architecture;

(ii) Solara Consolidated Master Fund GP LLC — a Delaware limited liability company to serve as the general partner of the Consolidated Master Fund;

(iii) Solara International Feeder (Cayman) LP — a Cayman Islands exempted limited partnership to serve as the feeder vehicle for non-U.S. investors; and

(iv) Solara Tax-Exempt Feeder (Cayman) LP — a Cayman Islands exempted limited partnership to serve as the feeder vehicle for U.S. tax-exempt investors.

The Reorganization involves a multi-step transaction that includes, among other things, asset contributions by the four offshore Legacy Fund Vehicles to the Consolidated Master Fund, the dissolution of the legacy offshore vehicles following such contributions, and the migration of existing limited partners into the appropriate new feeder structure. The target effective date for the completion of the Reorganization is December 1, 2025. The precise sequencing and mechanics of the multi-step transaction will be developed and refined in the course of the engagement, in consultation with the Client and its other advisors.

3.2 Scope of Legal Services

Calderwood & Harkness's engagement is limited to the following specific legal services in connection with the Reorganization:

(a) Tax Analysis Memoranda. Preparation of comprehensive tax analysis memoranda addressing the U.S. federal income tax consequences of the Reorganization under, among other provisions, Internal Revenue Code ("IRC") §§ 721(a), 721(b), 723, 731(a), 731(c), 704(c), 752, 367(a), 367(b), 1446, and 897, and Treasury Regulations § 301.7701-3. The tax analysis memoranda will address the characterization of each step of the multi-step Reorganization, including the contribution of assets by the offshore Legacy Fund Vehicles to the Consolidated Master Fund, the treatment of assumed or shifted liabilities, the application of the anti-mixing bowl rules, and the withholding tax implications for non-U.S. limited partners.

(b) Private Letter Ruling Request. Drafting, revising, and finalizing a private letter ruling request (the "PLR Request") to be submitted to the Internal Revenue Service's Office of the Associate Chief Counsel (International) ("CC:INTL"), with secondary jurisdiction in the Office of the Associate Chief Counsel (Passthroughs & Special Industries) ("CC:PSI"). The PLR Request will seek rulings on the specific tax consequences of the Reorganization that are identified in the course of the engagement as requiring advance IRS guidance for purposes of transaction certainty.

(c) Ancillary IRS Procedural Documents. Preparation and filing of all ancillary IRS procedural documents required in connection with the PLR Request, including IRS Forms 2848 (Powers of Attorney and Declarations of Representative), penalties of perjury declarations, user fee transmittals, and pre-submission and supplemental correspondence with the IRS.

(d) Pre-Submission Conference. Coordination and participation in a pre-submission conference with IRS CC:INTL (requested for July 22, 2025) and any follow-up communications arising therefrom. The pre-submission conference is intended to confirm the jurisdictional assignment of the PLR Request, identify any threshold legal issues, and facilitate an efficient review process following formal submission.

(e) Submission of PLR Request. Submission of the PLR Request to the IRS at the following address: Internal Revenue Service, Attn: CC:INTL, 1111 Constitution Avenue NW, Washington, DC 20224, together with all required enclosures, exhibits, and transmittal documents.

(f) Post-Submission Monitoring. Post-submission monitoring of the status of the PLR Request, preparation of responses to IRS information requests and additional questions, and supplemental submissions as necessary through issuance of the private letter ruling or closure of the matter by the IRS. This includes attendance at any conferences or telephone calls requested by the IRS examining branch.

(g) Coordination with Other Advisors. Coordination with the Client's other advisors as described in Section 3.3 below, to the extent necessary for the preparation and prosecution of the PLR Request and associated tax analysis memoranda.

(h) Supporting Documentation. Preparation of supporting documentation in connection with the Reorganization, including review of and comment on IRS Form 8832 (Entity Classification Election) filings for the New Fund Vehicles and any related check-the-box elections.

3.3 Coordination with Other Advisors

Calderwood & Harkness will coordinate with, but does not assume responsibility for the work of, the following advisors that have been retained by Solara or its affiliates in connection with the Reorganization or related matters. Each of the following advisors has been engaged separately by the Client, and the Firm's coordination with such advisors is limited to the exchange of information and consultation necessary for Calderwood & Harkness to perform the services described in Section 3.2:

(i) Caldwell Pierce & Co. LLP (400 Renaissance Center, Suite 2500, Detroit, MI 48243; Helen Okamoto, Partner) — independent accounting firm providing annual audits, tax compliance services, and supporting financial data for the PLR Request, including fund-level financial statements, capital account schedules, and partner allocation computations.

(ii) Redstone Advisory Group LLC (750 Seventh Avenue, 21st Floor, New York, NY 10019; Marco DeLuca, Managing Director) — valuation and transfer pricing advisory firm preparing fair market value appraisals of portfolio company interests and other assets to be contributed in connection with the Reorganization. Redstone's valuation reports will be included as exhibits to the PLR Request.

(iii) Meridian Offshore Legal (Caledonia House, 69 Dr. Roy's Drive, George Town, Grand Cayman KY1-1103; Fiona McAllister, Partner) — Cayman Islands counsel advising on the formation of the New Fund Vehicles organized in the Cayman Islands, the dissolution of the Legacy Fund Vehicles organized in the Cayman Islands, and related regulatory matters involving the Cayman Islands Monetary Authority ("CIMA").

(iv) Veldhuis & Gérard S.à r.l. (22, boulevard Royal, L-2449 Luxembourg; Marc Gérard, Managing Partner) — Luxembourg counsel advising on the dissolution of the Luxembourg SCSp vehicles and notification requirements to the Commission de Surveillance du Secteur Financier ("CSSF").

(v) Clarendon Fund Services Ltd. (Windward 3, Regatta Office Park, West Bay Road, George Town, Grand Cayman KY1-1108; Rachel Okonkwo, Client Relationship Director) — fund administrator for the offshore Legacy Fund Vehicles, providing net asset value computations, investor registries, and other administrative data relevant to the Reorganization.

Calderwood & Harkness will rely upon the work product of the foregoing advisors to the extent necessary for the preparation of the PLR Request and associated tax analysis memoranda. However, the Firm assumes no responsibility for the accuracy, completeness, or timeliness of work product prepared by any such advisor, and the Firm's reliance on such work product will be subject to the Firm's independent professional judgment.

3.4 Matters Excluded from Scope

For the avoidance of doubt, this engagement does not include the following:

(a) Legal advice on the laws of the Cayman Islands or Luxembourg, including corporate, partnership, regulatory, or tax law of those jurisdictions. Such matters are addressed by Meridian Offshore Legal and Veldhuis & Gérard S.à r.l., respectively, as described in Section 3.3 above.

(b) Ongoing tax compliance for any fund vehicle, including preparation of federal, state, or local tax returns, Schedules K-1, FATCA reporting (including IRS Forms W-8BEN, W-8BEN-E, and W-8IMY), or Common Reporting Standard ("CRS") reporting.

(c) Post-ruling implementation of the Reorganization, including without limitation the filing of formation documents, execution of contribution agreements, amendment and restatement of limited partnership agreements, or preparation or filing of dissolution documents, except to the extent specifically set forth in Section 3.2 above.

(d) Legal advice to, or representation of, any individual limited partner of any Legacy Fund Vehicle or New Fund Vehicle, the LP Advisory Committee of any fund (including the Fund IV LP Advisory Committee and the Fund V LP Advisory Committee), or any counterparty to any transaction involving Solara or its affiliates.

(e) State and local tax advice, including analysis of state income, franchise, or other tax consequences of the Reorganization in any U.S. state or local jurisdiction.

(f) Investment advice or securities law analysis, including advice under the Securities Act of 1933, the Securities Exchange Act of 1934, the Investment Advisers Act of 1940, the Investment Company Act of 1940, or any state "blue sky" laws.

If the Client wishes to expand the scope of this engagement to include any of the foregoing matters or any other matters not described in Section 3.2, the parties will enter into a separate engagement letter or written amendment to this Letter.

4. Engagement Team

The following attorneys of Calderwood & Harkness will serve as the engagement team for this matter:

Leonard Cross — Responsible Partner, Tax. Mr. Cross has twenty-eight (28) years of experience in international tax, partnership tax, and fund formation matters, with particular focus on cross-border restructurings, private letter ruling requests, and IRS controversy matters. Mr. Cross is located in Calderwood & Harkness's Washington, D.C. office at 1900 K Street NW, Suite 1100, Washington, DC 20006. He will serve as the primary point of contact for substantive tax matters and all communications with the IRS, including representation at the pre-submission conference and any subsequent IRS conferences or calls.

Sylvia Hartwell — Billing Partner, Tax. Ms. Hartwell has twenty-four (24) years of experience in cross-border restructurings and investment fund taxation, with deep expertise in multi-jurisdictional fund platform redesigns. Ms. Hartwell is located in Calderwood & Harkness's New York office at 600 Lexington Avenue, 38th Floor, New York, NY 10022. She will be responsible for billing, budget management, engagement administration, and overall client relationship management. Ms. Hartwell will also contribute to the substantive tax analysis as needed.

Robert Jansen — Lead Associate, Tax. Mr. Jansen has six (6) years of experience in tax law, with a focus on partnership taxation, entity classification, and IRS procedural matters. Mr. Jansen is located in the Firm's Washington, D.C. office. He will serve as the lead drafter of the PLR Request and tax analysis memoranda.

Garrett Simmons — Working Associate, Tax. Mr. Simmons has three (3) years of experience in tax law, with a focus on international tax research and financial modeling. Mr. Simmons is located in the Firm's New York office. He will provide research support, drafting assistance, and financial modeling in connection with the tax analysis memoranda and the PLR Request.

Calderwood & Harkness may, from time to time, engage additional attorneys or professional staff to assist with the matter as the needs of the engagement require. The Client will be notified of any material change to the staffing plan described above, including the assignment of any additional partner-level attorney to the engagement team. The Firm will endeavor to staff the engagement in a manner that balances efficiency, continuity, and the appropriate level of expertise for each task.

5. Fees and Billing

5.1 Hourly Rates

Legal services rendered in connection with this engagement will be billed at a blended hourly rate of $1,175.00 per hour for all engagement team members. The blended rate applies uniformly to all timekeepers assigned to the engagement, including partners, associates, counsel, and any other attorneys who may be assigned to the matter from time to time.

Calderwood & Harkness's standard billing rates are subject to annual adjustment, typically effective January 1 of each calendar year. Notwithstanding the foregoing, the blended rate of $1,175.00 per hour will be maintained for the duration of this engagement and will not be adjusted unless otherwise agreed in writing by both Calderwood & Harkness and the Client.

5.2 Estimated Fees

Based on the scope of services described in Section 3, Calderwood & Harkness estimates that total legal fees for this engagement will be in the range of $1,800,000 to $2,400,000. This estimate reflects the Firm's current understanding of the complexity of the Reorganization, the anticipated number of issues to be addressed in the PLR Request, and the expected level of IRS engagement.

This estimate is provided for budgeting purposes only and does not constitute a cap, maximum, fixed fee, or guaranteed price. The matter will be billed on a time-and-materials basis, and the Client will be responsible for actual fees incurred regardless of whether they fall within the estimated range.

Actual fees may be higher or lower than the estimate depending on a number of factors, including but not limited to: the complexity of tax issues encountered during the course of the engagement; the number of drafts of the PLR Request and tax analysis memoranda required; the extent and nature of IRS engagement, including the number and duration of conferences, information requests, and supplemental submissions; any expansion of the scope of services; and the availability and completeness of financial and transactional data provided by the Client and its other advisors.

Calderwood & Harkness will provide quarterly budget-to-actual comparisons to the Client and will promptly advise the Client if fees are projected to exceed the estimated range. The Firm will work collaboratively with the Client to manage costs and to ensure that the Client is informed of budgetary developments on a timely basis.

5.3 Fee Cap / Budget

There is no fee cap on this engagement. As noted in Section 5.2, the matter is billed on a time-and-materials basis. Quarterly budget updates will be provided to the Client, and the Firm will promptly notify the Client of any material developments that are expected to result in fees significantly exceeding the estimated range.

5.4 Disbursements and Expenses

In addition to professional fees, the Client will be responsible for reimbursement of all reasonable disbursements and out-of-pocket expenses incurred by Calderwood & Harkness in connection with the engagement. Estimated total disbursements for the engagement are approximately $85,000, and are expected to include the following categories:

(i) IRS User Fee: $38,000, payable in connection with the submission of the PLR Request. This amount reflects the current schedule of user fees applicable to ruling requests involving multiple entities with combined assets exceeding $50 million, as set forth in the IRS's annual revenue procedure governing letter ruling requests (Rev. Proc. 2025-1 equivalent).

(ii) Travel Expenses: Reasonable travel expenses for the pre-submission conference with IRS CC:INTL in Washington, D.C. (scheduled for July 22, 2025) and any subsequent IRS meetings or conferences, including airfare, hotel, ground transportation, and meals.

(iii) Courier and Filing Costs: Sundial Data Systems, courier, and filing costs associated with the submission of the PLR Request and related documents to the IRS.

(iv) Document Reproduction: Costs of copying, printing, and binding the PLR Request and exhibits for submission to the IRS, including production of multiple copies as required by IRS procedures.

(v) Electronic Research: Costs of electronic legal research (e.g., Westmark Data Systems, Tidewater Technologies, Sundial Solutions) incurred in connection with the engagement.

All disbursements will be billed at cost without markup. The Firm will exercise reasonable judgment in incurring disbursements and will seek the Client's prior approval for any individual disbursement exceeding $5,000 (other than the IRS user fee).

5.5 Billing Cycle and Payment Terms

Invoices for professional fees and disbursements will be rendered on a monthly basis, typically within fifteen (15) business days following the close of each calendar month.

Payment is due within thirty (30) days of the date of each invoice (net 30 days). Late payments may be subject to interest at the rate of 1.0% per month (12.0% per annum) on the outstanding balance, to the extent permitted by applicable law.

Each invoice will include detailed time entries reflecting the date of service, the name of the timekeeper, the number of hours billed, a narrative description of the services rendered, and the applicable hourly rate. Disbursements will be itemized separately.

All inquiries regarding invoices, billing, or payment should be directed to Sylvia Hartwell at (212) 554-8142 or shartwell@calderwoodharkness.com.

6. Matter Identification

This engagement has been assigned Calderwood & Harkness matter number 20250527-SDILP-PLR. All time entries, correspondence, work product, and billing will be recorded under this matter number. The Client should reference this matter number in all communications with the Firm regarding this engagement.

The matter has been opened in the Firm's records as of May 27, 2025. The administrative opening date reflects the Firm's internal processing timeline and does not alter the effective date of this engagement, which is as set forth in Section 1 above.

7. Key Milestones and Timeline

The following target milestones have been identified for the engagement in consultation with the Client:

The foregoing dates are targets and are subject to change based on the progress of the engagement, the availability of financial and transactional data from the Client and its advisors, and the IRS's scheduling of the pre-submission conference. Calderwood & Harkness will use commercially reasonable efforts to adhere to the timeline set forth above and will promptly advise the Client of any anticipated delays.

Post-submission milestones relating to entity formation, execution of transactional documents, and the implementation of the Reorganization steps are outside the primary scope of this engagement but will be coordinated with the Client as necessary. For reference, the Client has identified the following additional target dates: formation of the New Fund Vehicles (September 15, 2025) and the Step 5 effective date for completion of the Reorganization (December 1, 2025).

8. IRS Procedural Matters

The PLR Request will be submitted to the Office of the Associate Chief Counsel (International) ("CC:INTL") of the Internal Revenue Service, with secondary jurisdiction in the Office of the Associate Chief Counsel (Passthroughs & Special Industries) ("CC:PSI"). The jurisdictional assignment reflects the cross-border nature of the Reorganization and the involvement of both international tax provisions (including IRC §§ 367(a), 367(b), 1446, and 897) and partnership tax provisions (including IRC §§ 721, 723, 731, 704(c), and 752).

A pre-submission conference with IRS CC:INTL has been requested for July 22, 2025. The purpose of the pre-submission conference is to discuss the proposed PLR Request in general terms, confirm the jurisdictional assignment, identify any threshold legal or procedural issues, and facilitate an efficient post-submission review process. Mr. Cross and Mr. Jansen will attend the pre-submission conference on behalf of the Client.

IRS Forms 2848 (Power of Attorney and Declaration of Representative) will be filed with the IRS designating Leonard Cross and Sylvia Hartwell as authorized representatives for Solara Digital Infrastructure LP (EIN: 82-4917366), Solara Digital Infrastructure GP LLC (EIN: 82-4917365), and all related fund entities involved in the Reorganization. The Client will be asked to execute the Forms 2848 in advance of the pre-submission conference.

A penalties of perjury statement, as required by Rev. Proc. 2025-1 (or its equivalent) for submission of the PLR Request, will be required to be signed by Viktor Raines in his capacity as an authorized officer of Solara Digital Infrastructure GP LLC, the general partner of Solara Digital Infrastructure LP. Calderwood & Harkness will prepare the penalties of perjury statement and circulate it to the Client for execution prior to the submission date.

The IRS user fee of $38,000 will be submitted with the PLR Request by check or wire transfer payable to the United States Treasury. Calderwood & Harkness will advance this fee on behalf of the Client and will include it as a disbursement on the next monthly invoice following submission. The Client will be responsible for reimbursing the Firm for this amount in accordance with the payment terms set forth in Section 5.5.

9. Confidentiality and Attorney-Client Privilege

All communications between Calderwood & Harkness and the Client in connection with this engagement are intended to be privileged and confidential, protected by the attorney-client privilege, the work product doctrine, and any other applicable evidentiary or testimonial privileges. The Firm will take reasonable steps to maintain the confidentiality and privileged nature of all such communications and work product.

The Client agrees to maintain the confidentiality of all work product, memoranda, draft documents, analyses, and communications provided by Calderwood & Harkness in connection with this engagement. The Client should not disclose or disseminate such materials to any third party without first consulting with the engagement team regarding the potential impact on applicable privileges.

Disclosure of privileged or confidential materials to the Client's other advisors identified in Section 3.3 — namely, Caldwell Pierce & Co. LLP, Redstone Advisory Group LLC, Meridian Offshore Legal, Veldhuis & Gérard S.à r.l., and Clarendon Fund Services Ltd. — may be appropriate in certain circumstances to facilitate the engagement. However, such disclosures should be coordinated with Leonard Cross in advance to ensure that applicable privileges are preserved and that appropriate common interest, joint defense, or other protective arrangements are in place where necessary.

Similarly, any disclosure of engagement materials to the LP Advisory Committee's independent counsel, Whitfield, Carruthers & Doyle LLP (200 South Biscayne Boulevard, Suite 4000, Miami, FL 33131; Diana Carruthers, Partner), should be coordinated with the engagement team. The LP Advisory Committee's counsel represents the interests of the advisory committee members and not the Client, and disclosures to such counsel may implicate separate privilege considerations.

Communications with independent tax counsel retained by individual limited partners — for example, Bramhall & Quelwick LLP (44 Montgomery Street, Suite 3600, San Francisco, CA 94104; Jason Tremaine, Partner), which has been retained by Nordhaven Sovereign Wealth Fund — will be subject to separate privilege considerations. The Client should coordinate with the engagement team before sharing any Calderwood & Harkness work product or privileged communications with any limited partner's independent counsel to ensure that the Client's privileges are not inadvertently waived.

10. Conflicts of Interest

Calderwood & Harkness has conducted a conflicts check in accordance with the Firm's standard procedures and the applicable New York Rules of Professional Conduct. Based on the information provided by the Client, including the identities of the Legacy Fund Vehicles, the New Fund Vehicles, the engagement team members, and the Client's other advisors, no disqualifying conflicts of interest have been identified with respect to this engagement.

Calderwood & Harkness does not currently represent any party adverse to Solara, Solara GP, or any of the Legacy Fund Vehicles or New Fund Vehicles in any matter related to the Reorganization or in any other matter that would create a material conflict of interest under applicable professional responsibility rules.

The Firm's conflicts check is based on the information provided by the Client as of the date of this Letter. If a conflict of interest arises during the course of the engagement — whether as a result of new information, changes in the Firm's client base, or other developments — Calderwood & Harkness will promptly notify the Client and, if necessary, seek an appropriate informed consent waiver or withdraw from the engagement in whole or in part, in accordance with the applicable rules of professional conduct. The Client agrees to cooperate with the Firm in identifying and resolving any potential conflicts that may arise.

11. Document Retention

Calderwood & Harkness will retain engagement files in accordance with its standard document retention policies, which are consistent with the Firm's obligations under applicable rules of professional conduct and any other legal requirements. Engagement files may include correspondence, memoranda, drafts, research materials, billing records, and other documents created or received in connection with the engagement.

Upon conclusion of the engagement, the Client may request the return or delivery of original documents provided to the Firm by the Client. Copies of work product prepared by Calderwood & Harkness will be retained by the Firm for a period consistent with the Firm's professional obligations. The Firm reserves the right to destroy engagement files after the expiration of the applicable retention period, subject to any legal hold or preservation obligation then in effect.

12. Limitation of Engagement

Calderwood & Harkness's representation in this engagement is limited to the specific scope described in Section 3 of this Letter. The Firm does not, by virtue of this engagement, undertake to represent the Client in any other matter, nor does the Firm assume any obligation to advise the Client on developments in law or regulation outside the scope of this engagement.

Calderwood & Harkness does not represent any individual partner, officer, director, manager, or employee of Solara, Solara GP, or any of the Legacy Fund Vehicles or New Fund Vehicles in their personal capacity. Any such individual who requires personal legal advice in connection with the Reorganization or otherwise should retain independent counsel.

Calderwood & Harkness does not represent, and will not provide legal advice to, any limited partner of any fund vehicle, including without limitation the following institutional investors: Pinnacle State Employees' Retirement System, Grandview University Endowment, Nordhaven Sovereign Wealth Fund, Kestrel Pacific Insurance Group, Argyle Family Office Holdings LLC, or any other limited partner or investor in any Legacy Fund Vehicle or New Fund Vehicle. Each such limited partner should consult its own legal, tax, and financial advisors regarding the Reorganization and its impact on such limited partner's investment.

Calderwood & Harkness does not represent any lender, credit facility party, or other financing source, including without limitation Ashford National Bank, N.A. or Sentinel Capital Markets LLC, in connection with this engagement or any related matter.

This engagement does not include advice on insurance coverage matters. The Client has advised Calderwood & Harkness that Solara maintains directors' and officers' / errors and omissions liability insurance coverage with an aggregate limit of $50 million, placed with Hawkstone Specialty Insurance Co. Analysis of such coverage, or any other insurance matters, is outside the scope of this engagement.

13. Termination

Either party may terminate this engagement at any time upon written notice to the other party. Termination by the Client shall be effective upon receipt of written notice by Calderwood & Harkness. Termination by the Firm shall be effective upon reasonable notice to the Client, taking into account the status of any pending IRS submission or correspondence and the need to protect the Client's interests during any transition period.

Upon termination, the Client will remain responsible for payment of all fees incurred and disbursements advanced through the date of termination, in accordance with the billing and payment terms set forth in Section 5. Calderwood & Harkness will render a final invoice within thirty (30) days following the effective date of termination.

In the event of termination while IRS proceedings are pending, Calderwood & Harkness will take reasonable steps to protect the Client's interests, including providing the Client with copies of all pending submissions and correspondence, notifying the IRS of the change in representation as required by applicable procedures, and cooperating with successor counsel to facilitate an orderly transition.

14. Governing Law

This engagement letter shall be governed by and construed in accordance with the laws of the State of New York, without regard to its conflict of laws principles. Any dispute arising out of or relating to this Letter or the engagement described herein shall be subject to the exclusive jurisdiction of the courts of the State of New York located in the County of New York or the United States District Court for the Southern District of New York.

15. Entire Agreement

This Letter constitutes the entire agreement between Calderwood & Harkness LLP and Solara Digital Infrastructure LP (together with Solara Digital Infrastructure GP LLC) with respect to the engagement described herein and supersedes all prior negotiations, representations, warranties, commitments, offers, and agreements (whether oral or written) relating to the subject matter hereof.

Any amendment, modification, or supplement to this Letter must be in writing and signed by both Calderwood & Harkness and the Client. No waiver of any provision of this Letter shall be effective unless set forth in a writing signed by the party against whom enforcement is sought.

We look forward to working with you and your team on this important matter. We believe Calderwood & Harkness is well positioned to deliver the high-quality, efficient legal services that Solara requires in connection with the Reorganization, and we are committed to achieving a successful outcome for the Client.

If the foregoing accurately reflects your understanding of our engagement, please sign and return a copy of this letter to the undersigned at your earliest convenience.

Very truly yours,

CALDERWOOD & HARKNESS LLP

By: ________

Name: Sylvia Hartwell

Title: Partner

Date: ________

AGREED AND ACCEPTED:

SOLARA DIGITAL INFRASTRUCTURE LP

By: Solara Digital Infrastructure GP LLC,

its General Partner

By: ________

Name: Priya Narasimhan

Title: General Counsel

Date: ________

cc: Viktor Raines, Managing Partner & Founder, Solara Digital Infrastructure LP cc: Stefan Dalmqvist, Head of Tax, Solara Digital Infrastructure LP cc: Leonard Cross, Partner, Calderwood & Harkness LLP cc: Robert Jansen, Associate, Calderwood & Harkness LLP

Target Date	Milestone
June 16, 2025	Completion of initial comprehensive tax analysis memorandum
July 1, 2025	Circulation of draft PLR Request (Version 1.0) to Client for review
July 15, 2025	LPAC review of final PLR Request draft
July 22, 2025	Pre-submission conference with IRS CC:INTL Branch 1
August 15, 2025	Submission of PLR Request to IRS

CALDERWOOD & HARKNESS LLP Attorneys at Law
600 Lexington Avenue, 38th Floor New York, New York 10022
Telephone: (212) 554-8000 Facsimile: (212) 554-8001 www.calderwoodharkness.com
May 12, 2025
VIA EMAIL AND Sundial Data Systems
Priya Narasimhan, Esq. General Counsel Solara Digital Infrastructure LP 1200 Market Street, Suite 3400 Wilmington, Delaware 19801
Re: Engagement of Calderwood & Harkness LLP — Private Letter Ruling Request in Connection with Cross-Border Fund-Platform Reorganization of Solara Digital Infrastructure LP
Engagement Number: 20250527-SDILP-PLR
Dear Ms. Narasimhan:
1. Purpose and Acceptance
Calderwood & Harkness LLP ("Calderwood & Harkness" or the "Firm") is pleased to confirm its engagement by Solara Digital Infrastructure LP ("Solara" or "SDILP"), a Delaware limited partnership, and its general partner, Solara Digital Infrastructure GP LLC ("Solara GP"), a Delaware limited liability company (collectively, the "Client"), to provide the legal services described in this engagement letter (this "Letter"). We appreciate the confidence that Solara and Solara GP have placed in our Firm, and we look forward to working with your team on this significant and complex matter.
This Letter sets forth the terms and conditions upon which Calderwood & Harkness will provide legal services in connection with the matter described herein. By countersigning this Letter in the space provided below, the Client agrees to be bound by the terms and conditions set forth herein. This engagement shall be effective as of the date of the countersignature below. No attorney-client relationship will be deemed to have been established with respect to the matter described herein until this Letter has been signed by an authorized representative of the Client and returned to the Firm.
2. Description of the Client
The client for this engagement is Solara Digital Infrastructure LP (EIN: 82-4917366) and Solara Digital Infrastructure GP LLC (EIN: 82-4917365). For the avoidance of doubt, the "Client" as used throughout this Letter refers collectively to SDILP and Solara GP, except where the context clearly requires otherwise.
Solara is a Delaware-based private equity sponsor with approximately $14.7 billion in assets under management as of March 31, 2025, operating across digital infrastructure and enterprise SaaS verticals. Solara sponsors private equity funds through a series of parallel fund structures established across Delaware, the Cayman Islands, and Luxembourg to accommodate U.S. taxable, U.S. tax-exempt, and non-U.S. investor pools. The fund platform reflects a multi-jurisdictional architecture that is common among institutional-scale private equity sponsors and is central to the reorganization that is the subject of this engagement.
The principal contact persons at Solara for purposes of this engagement are as follows:
•  Priya Narasimhan, General Counsel — primary legal contact and authorized decision-maker for engagement-related matters;
•  Stefan Dalmqvist, Head of Tax — primary contact for substantive tax matters, financial data, and coordination with the Client's independent auditors and valuation advisors.
The Managing Partner and Founder of Solara is Viktor Raines. Mr. Raines will serve as the authorized officer of Solara Digital Infrastructure GP LLC for purposes of executing any penalties of perjury declarations and other representations required in connection with Internal Revenue Service ("IRS") submissions, as described more fully in Section 8 below.
All communications from the Firm regarding this engagement should be directed to Ms. Narasimhan and Mr. Dalmqvist, unless otherwise instructed in writing by the Client.
3. Scope of Engagement
3.1 Overview of the Transaction
Solara is undertaking a cross-border reorganization of its fund platform (the "Reorganization"), involving the domestication and merger of several Cayman Islands and Luxembourg fund vehicles into a newly established Delaware-domiciled master fund structure. The Reorganization is designed to simplify the Client's fund architecture, reduce administrative and operational costs, enhance investor reporting, and achieve certain tax efficiencies in connection with the ongoing management and eventual disposition of portfolio company interests.
The Reorganization involves the following existing fund vehicles (collectively, the "Legacy Fund Vehicles"):
(i) Solara Digital Partners Fund IV LP — a Delaware limited partnership with approximately $4.2 billion in committed capital (vintage 2021), approximately 72% deployed as of the date hereof;
(ii) Solara Digital Partners Fund IV-A (Cayman) LP — a Cayman Islands exempted limited partnership with approximately $1.85 billion in committed capital, operating as a parallel fund to Fund IV for U.S. tax-exempt and non-U.S. investors;
(iii) Solara Digital Partners Fund IV-B (Luxembourg) SCSp — a Luxembourg special limited partnership (société en commandite spéciale) with approximately €1.15 billion in committed capital (approximately $1.24 billion at an assumed exchange rate of 1.08 EUR/USD), operating as a parallel fund to Fund IV for certain European institutional investors;
(iv) Solara Digital Partners Fund V LP — a Delaware limited partnership with approximately $5.6 billion in committed capital (vintage 2023), approximately 38% deployed as of the date hereof;
(v) Solara Digital Partners Fund V-A (Cayman) LP — a Cayman Islands exempted limited partnership with approximately $2.45 billion in committed capital, operating as a parallel fund to Fund V for U.S. tax-exempt and non-U.S. investors; and
(vi) Solara Digital Partners Fund V-B (Luxembourg) SCSp — a Luxembourg special limited partnership (société en commandite spéciale) with approximately €1.38 billion in committed capital (approximately $1.49 billion at an assumed exchange rate of 1.08 EUR/USD), operating as a parallel fund to Fund V for certain European institutional investors.
The Reorganization contemplates the formation of the following new entities (collectively, the "New Fund Vehicles"):
(i) Solara Consolidated Master Fund LP — a Delaware limited partnership to serve as the master fund in a restructured master-feeder architecture;
(ii) Solara Consolidated Master Fund GP LLC — a Delaware limited liability company to serve as the general partner of the Consolidated Master Fund;
(iii) Solara International Feeder (Cayman) LP — a Cayman Islands exempted limited partnership to serve as the feeder vehicle for non-U.S. investors; and
(iv) Solara Tax-Exempt Feeder (Cayman) LP — a Cayman Islands exempted limited partnership to serve as the feeder vehicle for U.S. tax-exempt investors.
The Reorganization involves a multi-step transaction that includes, among other things, asset contributions by the four offshore Legacy Fund Vehicles to the Consolidated Master Fund, the dissolution of the legacy offshore vehicles following such contributions, and the migration of existing limited partners into the appropriate new feeder structure. The target effective date for the completion of the Reorganization is December 1, 2025. The precise sequencing and mechanics of the multi-step transaction will be developed and refined in the course of the engagement, in consultation with the Client and its other advisors.
3.2 Scope of Legal Services
Calderwood & Harkness's engagement is limited to the following specific legal services in connection with the Reorganization:
(a) Tax Analysis Memoranda. Preparation of comprehensive tax analysis memoranda addressing the U.S. federal income tax consequences of the Reorganization under, among other provisions, Internal Revenue Code ("IRC") §§ 721(a), 721(b), 723, 731(a), 731(c), 704(c), 752, 367(a), 367(b), 1446, and 897, and Treasury Regulations § 301.7701-3. The tax analysis memoranda will address the characterization of each step of the multi-step Reorganization, including the contribution of assets by the offshore Legacy Fund Vehicles to the Consolidated Master Fund, the treatment of assumed or shifted liabilities, the application of the anti-mixing bowl rules, and the withholding tax implications for non-U.S. limited partners.
(b) Private Letter Ruling Request. Drafting, revising, and finalizing a private letter ruling request (the "PLR Request") to be submitted to the Internal Revenue Service's Office of the Associate Chief Counsel (International) ("CC:INTL"), with secondary jurisdiction in the Office of the Associate Chief Counsel (Passthroughs & Special Industries) ("CC:PSI"). The PLR Request will seek rulings on the specific tax consequences of the Reorganization that are identified in the course of the engagement as requiring advance IRS guidance for purposes of transaction certainty.
(c) Ancillary IRS Procedural Documents. Preparation and filing of all ancillary IRS procedural documents required in connection with the PLR Request, including IRS Forms 2848 (Powers of Attorney and Declarations of Representative), penalties of perjury declarations, user fee transmittals, and pre-submission and supplemental correspondence with the IRS.
(d) Pre-Submission Conference. Coordination and participation in a pre-submission conference with IRS CC:INTL (requested for July 22, 2025) and any follow-up communications arising therefrom. The pre-submission conference is intended to confirm the jurisdictional assignment of the PLR Request, identify any threshold legal issues, and facilitate an efficient review process following formal submission.
(e) Submission of PLR Request. Submission of the PLR Request to the IRS at the following address: Internal Revenue Service, Attn: CC:INTL, 1111 Constitution Avenue NW, Washington, DC 20224, together with all required enclosures, exhibits, and transmittal documents.
(f) Post-Submission Monitoring. Post-submission monitoring of the status of the PLR Request, preparation of responses to IRS information requests and additional questions, and supplemental submissions as necessary through issuance of the private letter ruling or closure of the matter by the IRS. This includes attendance at any conferences or telephone calls requested by the IRS examining branch.
(g) Coordination with Other Advisors. Coordination with the Client's other advisors as described in Section 3.3 below, to the extent necessary for the preparation and prosecution of the PLR Request and associated tax analysis memoranda.
(h) Supporting Documentation. Preparation of supporting documentation in connection with the Reorganization, including review of and comment on IRS Form 8832 (Entity Classification Election) filings for the New Fund Vehicles and any related check-the-box elections.
3.3 Coordination with Other Advisors
Calderwood & Harkness will coordinate with, but does not assume responsibility for the work of, the following advisors that have been retained by Solara or its affiliates in connection with the Reorganization or related matters. Each of the following advisors has been engaged separately by the Client, and the Firm's coordination with such advisors is limited to the exchange of information and consultation necessary for Calderwood & Harkness to perform the services described in Section 3.2:
(i) Caldwell Pierce & Co. LLP (400 Renaissance Center, Suite 2500, Detroit, MI 48243; Helen Okamoto, Partner) — independent accounting firm providing annual audits, tax compliance services, and supporting financial data for the PLR Request, including fund-level financial statements, capital account schedules, and partner allocation computations.
(ii) Redstone Advisory Group LLC (750 Seventh Avenue, 21st Floor, New York, NY 10019; Marco DeLuca, Managing Director) — valuation and transfer pricing advisory firm preparing fair market value appraisals of portfolio company interests and other assets to be contributed in connection with the Reorganization. Redstone's valuation reports will be included as exhibits to the PLR Request.
(iii) Meridian Offshore Legal (Caledonia House, 69 Dr. Roy's Drive, George Town, Grand Cayman KY1-1103; Fiona McAllister, Partner) — Cayman Islands counsel advising on the formation of the New Fund Vehicles organized in the Cayman Islands, the dissolution of the Legacy Fund Vehicles organized in the Cayman Islands, and related regulatory matters involving the Cayman Islands Monetary Authority ("CIMA").
(iv) Veldhuis & Gérard S.à r.l. (22, boulevard Royal, L-2449 Luxembourg; Marc Gérard, Managing Partner) — Luxembourg counsel advising on the dissolution of the Luxembourg SCSp vehicles and notification requirements to the Commission de Surveillance du Secteur Financier ("CSSF").
(v) Clarendon Fund Services Ltd. (Windward 3, Regatta Office Park, West Bay Road, George Town, Grand Cayman KY1-1108; Rachel Okonkwo, Client Relationship Director) — fund administrator for the offshore Legacy Fund Vehicles, providing net asset value computations, investor registries, and other administrative data relevant to the Reorganization.
Calderwood & Harkness will rely upon the work product of the foregoing advisors to the extent necessary for the preparation of the PLR Request and associated tax analysis memoranda. However, the Firm assumes no responsibility for the accuracy, completeness, or timeliness of work product prepared by any such advisor, and the Firm's reliance on such work product will be subject to the Firm's independent professional judgment.
3.4 Matters Excluded from Scope
For the avoidance of doubt, this engagement does not include the following:
(a) Legal advice on the laws of the Cayman Islands or Luxembourg, including corporate, partnership, regulatory, or tax law of those jurisdictions. Such matters are addressed by Meridian Offshore Legal and Veldhuis & Gérard S.à r.l., respectively, as described in Section 3.3 above.
(b) Ongoing tax compliance for any fund vehicle, including preparation of federal, state, or local tax returns, Schedules K-1, FATCA reporting (including IRS Forms W-8BEN, W-8BEN-E, and W-8IMY), or Common Reporting Standard ("CRS") reporting.
(c) Post-ruling implementation of the Reorganization, including without limitation the filing of formation documents, execution of contribution agreements, amendment and restatement of limited partnership agreements, or preparation or filing of dissolution documents, except to the extent specifically set forth in Section 3.2 above.
(d) Legal advice to, or representation of, any individual limited partner of any Legacy Fund Vehicle or New Fund Vehicle, the LP Advisory Committee of any fund (including the Fund IV LP Advisory Committee and the Fund V LP Advisory Committee), or any counterparty to any transaction involving Solara or its affiliates.
(e) State and local tax advice, including analysis of state income, franchise, or other tax consequences of the Reorganization in any U.S. state or local jurisdiction.
(f) Investment advice or securities law analysis, including advice under the Securities Act of 1933, the Securities Exchange Act of 1934, the Investment Advisers Act of 1940, the Investment Company Act of 1940, or any state "blue sky" laws.
If the Client wishes to expand the scope of this engagement to include any of the foregoing matters or any other matters not described in Section 3.2, the parties will enter into a separate engagement letter or written amendment to this Letter.
4. Engagement Team
The following attorneys of Calderwood & Harkness will serve as the engagement team for this matter:
Leonard Cross — Responsible Partner, Tax. Mr. Cross has twenty-eight (28) years of experience in international tax, partnership tax, and fund formation matters, with particular focus on cross-border restructurings, private letter ruling requests, and IRS controversy matters. Mr. Cross is located in Calderwood & Harkness's Washington, D.C. office at 1900 K Street NW, Suite 1100, Washington, DC 20006. He will serve as the primary point of contact for substantive tax matters and all communications with the IRS, including representation at the pre-submission conference and any subsequent IRS conferences or calls.
Sylvia Hartwell — Billing Partner, Tax. Ms. Hartwell has twenty-four (24) years of experience in cross-border restructurings and investment fund taxation, with deep expertise in multi-jurisdictional fund platform redesigns. Ms. Hartwell is located in Calderwood & Harkness's New York office at 600 Lexington Avenue, 38th Floor, New York, NY 10022. She will be responsible for billing, budget management, engagement administration, and overall client relationship management. Ms. Hartwell will also contribute to the substantive tax analysis as needed.
Robert Jansen — Lead Associate, Tax. Mr. Jansen has six (6) years of experience in tax law, with a focus on partnership taxation, entity classification, and IRS procedural matters. Mr. Jansen is located in the Firm's Washington, D.C. office. He will serve as the lead drafter of the PLR Request and tax analysis memoranda.
Garrett Simmons — Working Associate, Tax. Mr. Simmons has three (3) years of experience in tax law, with a focus on international tax research and financial modeling. Mr. Simmons is located in the Firm's New York office. He will provide research support, drafting assistance, and financial modeling in connection with the tax analysis memoranda and the PLR Request.
Calderwood & Harkness may, from time to time, engage additional attorneys or professional staff to assist with the matter as the needs of the engagement require. The Client will be notified of any material change to the staffing plan described above, including the assignment of any additional partner-level attorney to the engagement team. The Firm will endeavor to staff the engagement in a manner that balances efficiency, continuity, and the appropriate level of expertise for each task.
5. Fees and Billing
5.1 Hourly Rates
Legal services rendered in connection with this engagement will be billed at a blended hourly rate of $1,175.00 per hour for all engagement team members. The blended rate applies uniformly to all timekeepers assigned to the engagement, including partners, associates, counsel, and any other attorneys who may be assigned to the matter from time to time.
Calderwood & Harkness's standard billing rates are subject to annual adjustment, typically effective January 1 of each calendar year. Notwithstanding the foregoing, the blended rate of $1,175.00 per hour will be maintained for the duration of this engagement and will not be adjusted unless otherwise agreed in writing by both Calderwood & Harkness and the Client.
5.2 Estimated Fees
Based on the scope of services described in Section 3, Calderwood & Harkness estimates that total legal fees for this engagement will be in the range of $1,800,000 to $2,400,000. This estimate reflects the Firm's current understanding of the complexity of the Reorganization, the anticipated number of issues to be addressed in the PLR Request, and the expected level of IRS engagement.
This estimate is provided for budgeting purposes only and does not constitute a cap, maximum, fixed fee, or guaranteed price. The matter will be billed on a time-and-materials basis, and the Client will be responsible for actual fees incurred regardless of whether they fall within the estimated range.
Actual fees may be higher or lower than the estimate depending on a number of factors, including but not limited to: the complexity of tax issues encountered during the course of the engagement; the number of drafts of the PLR Request and tax analysis memoranda required; the extent and nature of IRS engagement, including the number and duration of conferences, information requests, and supplemental submissions; any expansion of the scope of services; and the availability and completeness of financial and transactional data provided by the Client and its other advisors.
Calderwood & Harkness will provide quarterly budget-to-actual comparisons to the Client and will promptly advise the Client if fees are projected to exceed the estimated range. The Firm will work collaboratively with the Client to manage costs and to ensure that the Client is informed of budgetary developments on a timely basis.
5.3 Fee Cap / Budget
There is no fee cap on this engagement. As noted in Section 5.2, the matter is billed on a time-and-materials basis. Quarterly budget updates will be provided to the Client, and the Firm will promptly notify the Client of any material developments that are expected to result in fees significantly exceeding the estimated range.
5.4 Disbursements and Expenses
In addition to professional fees, the Client will be responsible for reimbursement of all reasonable disbursements and out-of-pocket expenses incurred by Calderwood & Harkness in connection with the engagement. Estimated total disbursements for the engagement are approximately $85,000, and are expected to include the following categories:
(i) IRS User Fee: $38,000, payable in connection with the submission of the PLR Request. This amount reflects the current schedule of user fees applicable to ruling requests involving multiple entities with combined assets exceeding $50 million, as set forth in the IRS's annual revenue procedure governing letter ruling requests (Rev. Proc. 2025-1 equivalent).
(ii) Travel Expenses: Reasonable travel expenses for the pre-submission conference with IRS CC:INTL in Washington, D.C. (scheduled for July 22, 2025) and any subsequent IRS meetings or conferences, including airfare, hotel, ground transportation, and meals.
(iii) Courier and Filing Costs: Sundial Data Systems, courier, and filing costs associated with the submission of the PLR Request and related documents to the IRS.
(iv) Document Reproduction: Costs of copying, printing, and binding the PLR Request and exhibits for submission to the IRS, including production of multiple copies as required by IRS procedures.
(v) Electronic Research: Costs of electronic legal research (e.g., Westmark Data Systems, Tidewater Technologies, Sundial Solutions) incurred in connection with the engagement.
All disbursements will be billed at cost without markup. The Firm will exercise reasonable judgment in incurring disbursements and will seek the Client's prior approval for any individual disbursement exceeding $5,000 (other than the IRS user fee).
5.5 Billing Cycle and Payment Terms
Invoices for professional fees and disbursements will be rendered on a monthly basis, typically within fifteen (15) business days following the close of each calendar month.
Payment is due within thirty (30) days of the date of each invoice (net 30 days). Late payments may be subject to interest at the rate of 1.0% per month (12.0% per annum) on the outstanding balance, to the extent permitted by applicable law.
Each invoice will include detailed time entries reflecting the date of service, the name of the timekeeper, the number of hours billed, a narrative description of the services rendered, and the applicable hourly rate. Disbursements will be itemized separately.
All inquiries regarding invoices, billing, or payment should be directed to Sylvia Hartwell at (212) 554-8142 or shartwell@calderwoodharkness.com.
6. Matter Identification
This engagement has been assigned Calderwood & Harkness matter number 20250527-SDILP-PLR. All time entries, correspondence, work product, and billing will be recorded under this matter number. The Client should reference this matter number in all communications with the Firm regarding this engagement.
The matter has been opened in the Firm's records as of May 27, 2025. The administrative opening date reflects the Firm's internal processing timeline and does not alter the effective date of this engagement, which is as set forth in Section 1 above.
7. Key Milestones and Timeline
The following target milestones have been identified for the engagement in consultation with the Client:
The foregoing dates are targets and are subject to change based on the progress of the engagement, the availability of financial and transactional data from the Client and its advisors, and the IRS's scheduling of the pre-submission conference. Calderwood & Harkness will use commercially reasonable efforts to adhere to the timeline set forth above and will promptly advise the Client of any anticipated delays.
Post-submission milestones relating to entity formation, execution of transactional documents, and the implementation of the Reorganization steps are outside the primary scope of this engagement but will be coordinated with the Client as necessary. For reference, the Client has identified the following additional target dates: formation of the New Fund Vehicles (September 15, 2025) and the Step 5 effective date for completion of the Reorganization (December 1, 2025).
8. IRS Procedural Matters
The PLR Request will be submitted to the Office of the Associate Chief Counsel (International) ("CC:INTL") of the Internal Revenue Service, with secondary jurisdiction in the Office of the Associate Chief Counsel (Passthroughs & Special Industries) ("CC:PSI"). The jurisdictional assignment reflects the cross-border nature of the Reorganization and the involvement of both international tax provisions (including IRC §§ 367(a), 367(b), 1446, and 897) and partnership tax provisions (including IRC §§ 721, 723, 731, 704(c), and 752).
A pre-submission conference with IRS CC:INTL has been requested for July 22, 2025. The purpose of the pre-submission conference is to discuss the proposed PLR Request in general terms, confirm the jurisdictional assignment, identify any threshold legal or procedural issues, and facilitate an efficient post-submission review process. Mr. Cross and Mr. Jansen will attend the pre-submission conference on behalf of the Client.
IRS Forms 2848 (Power of Attorney and Declaration of Representative) will be filed with the IRS designating Leonard Cross and Sylvia Hartwell as authorized representatives for Solara Digital Infrastructure LP (EIN: 82-4917366), Solara Digital Infrastructure GP LLC (EIN: 82-4917365), and all related fund entities involved in the Reorganization. The Client will be asked to execute the Forms 2848 in advance of the pre-submission conference.
A penalties of perjury statement, as required by Rev. Proc. 2025-1 (or its equivalent) for submission of the PLR Request, will be required to be signed by Viktor Raines in his capacity as an authorized officer of Solara Digital Infrastructure GP LLC, the general partner of Solara Digital Infrastructure LP. Calderwood & Harkness will prepare the penalties of perjury statement and circulate it to the Client for execution prior to the submission date.
The IRS user fee of $38,000 will be submitted with the PLR Request by check or wire transfer payable to the United States Treasury. Calderwood & Harkness will advance this fee on behalf of the Client and will include it as a disbursement on the next monthly invoice following submission. The Client will be responsible for reimbursing the Firm for this amount in accordance with the payment terms set forth in Section 5.5.
9. Confidentiality and Attorney-Client Privilege
All communications between Calderwood & Harkness and the Client in connection with this engagement are intended to be privileged and confidential, protected by the attorney-client privilege, the work product doctrine, and any other applicable evidentiary or testimonial privileges. The Firm will take reasonable steps to maintain the confidentiality and privileged nature of all such communications and work product.
The Client agrees to maintain the confidentiality of all work product, memoranda, draft documents, analyses, and communications provided by Calderwood & Harkness in connection with this engagement. The Client should not disclose or disseminate such materials to any third party without first consulting with the engagement team regarding the potential impact on applicable privileges.
Disclosure of privileged or confidential materials to the Client's other advisors identified in Section 3.3 — namely, Caldwell Pierce & Co. LLP, Redstone Advisory Group LLC, Meridian Offshore Legal, Veldhuis & Gérard S.à r.l., and Clarendon Fund Services Ltd. — may be appropriate in certain circumstances to facilitate the engagement. However, such disclosures should be coordinated with Leonard Cross in advance to ensure that applicable privileges are preserved and that appropriate common interest, joint defense, or other protective arrangements are in place where necessary.
Similarly, any disclosure of engagement materials to the LP Advisory Committee's independent counsel, Whitfield, Carruthers & Doyle LLP (200 South Biscayne Boulevard, Suite 4000, Miami, FL 33131; Diana Carruthers, Partner), should be coordinated with the engagement team. The LP Advisory Committee's counsel represents the interests of the advisory committee members and not the Client, and disclosures to such counsel may implicate separate privilege considerations.
Communications with independent tax counsel retained by individual limited partners — for example, Bramhall & Quelwick LLP (44 Montgomery Street, Suite 3600, San Francisco, CA 94104; Jason Tremaine, Partner), which has been retained by Nordhaven Sovereign Wealth Fund — will be subject to separate privilege considerations. The Client should coordinate with the engagement team before sharing any Calderwood & Harkness work product or privileged communications with any limited partner's independent counsel to ensure that the Client's privileges are not inadvertently waived.
10. Conflicts of Interest
Calderwood & Harkness has conducted a conflicts check in accordance with the Firm's standard procedures and the applicable New York Rules of Professional Conduct. Based on the information provided by the Client, including the identities of the Legacy Fund Vehicles, the New Fund Vehicles, the engagement team members, and the Client's other advisors, no disqualifying conflicts of interest have been identified with respect to this engagement.
Calderwood & Harkness does not currently represent any party adverse to Solara, Solara GP, or any of the Legacy Fund Vehicles or New Fund Vehicles in any matter related to the Reorganization or in any other matter that would create a material conflict of interest under applicable professional responsibility rules.
The Firm's conflicts check is based on the information provided by the Client as of the date of this Letter. If a conflict of interest arises during the course of the engagement — whether as a result of new information, changes in the Firm's client base, or other developments — Calderwood & Harkness will promptly notify the Client and, if necessary, seek an appropriate informed consent waiver or withdraw from the engagement in whole or in part, in accordance with the applicable rules of professional conduct. The Client agrees to cooperate with the Firm in identifying and resolving any potential conflicts that may arise.
11. Document Retention
Calderwood & Harkness will retain engagement files in accordance with its standard document retention policies, which are consistent with the Firm's obligations under applicable rules of professional conduct and any other legal requirements. Engagement files may include correspondence, memoranda, drafts, research materials, billing records, and other documents created or received in connection with the engagement.
Upon conclusion of the engagement, the Client may request the return or delivery of original documents provided to the Firm by the Client. Copies of work product prepared by Calderwood & Harkness will be retained by the Firm for a period consistent with the Firm's professional obligations. The Firm reserves the right to destroy engagement files after the expiration of the applicable retention period, subject to any legal hold or preservation obligation then in effect.
12. Limitation of Engagement
Calderwood & Harkness's representation in this engagement is limited to the specific scope described in Section 3 of this Letter. The Firm does not, by virtue of this engagement, undertake to represent the Client in any other matter, nor does the Firm assume any obligation to advise the Client on developments in law or regulation outside the scope of this engagement.
Calderwood & Harkness does not represent any individual partner, officer, director, manager, or employee of Solara, Solara GP, or any of the Legacy Fund Vehicles or New Fund Vehicles in their personal capacity. Any such individual who requires personal legal advice in connection with the Reorganization or otherwise should retain independent counsel.
Calderwood & Harkness does not represent, and will not provide legal advice to, any limited partner of any fund vehicle, including without limitation the following institutional investors: Pinnacle State Employees' Retirement System, Grandview University Endowment, Nordhaven Sovereign Wealth Fund, Kestrel Pacific Insurance Group, Argyle Family Office Holdings LLC, or any other limited partner or investor in any Legacy Fund Vehicle or New Fund Vehicle. Each such limited partner should consult its own legal, tax, and financial advisors regarding the Reorganization and its impact on such limited partner's investment.
Calderwood & Harkness does not represent any lender, credit facility party, or other financing source, including without limitation Ashford National Bank, N.A. or Sentinel Capital Markets LLC, in connection with this engagement or any related matter.
This engagement does not include advice on insurance coverage matters. The Client has advised Calderwood & Harkness that Solara maintains directors' and officers' / errors and omissions liability insurance coverage with an aggregate limit of $50 million, placed with Hawkstone Specialty Insurance Co. Analysis of such coverage, or any other insurance matters, is outside the scope of this engagement.
13. Termination
Either party may terminate this engagement at any time upon written notice to the other party. Termination by the Client shall be effective upon receipt of written notice by Calderwood & Harkness. Termination by the Firm shall be effective upon reasonable notice to the Client, taking into account the status of any pending IRS submission or correspondence and the need to protect the Client's interests during any transition period.
Upon termination, the Client will remain responsible for payment of all fees incurred and disbursements advanced through the date of termination, in accordance with the billing and payment terms set forth in Section 5. Calderwood & Harkness will render a final invoice within thirty (30) days following the effective date of termination.
In the event of termination while IRS proceedings are pending, Calderwood & Harkness will take reasonable steps to protect the Client's interests, including providing the Client with copies of all pending submissions and correspondence, notifying the IRS of the change in representation as required by applicable procedures, and cooperating with successor counsel to facilitate an orderly transition.
14. Governing Law
This engagement letter shall be governed by and construed in accordance with the laws of the State of New York, without regard to its conflict of laws principles. Any dispute arising out of or relating to this Letter or the engagement described herein shall be subject to the exclusive jurisdiction of the courts of the State of New York located in the County of New York or the United States District Court for the Southern District of New York.
15. Entire Agreement
This Letter constitutes the entire agreement between Calderwood & Harkness LLP and Solara Digital Infrastructure LP (together with Solara Digital Infrastructure GP LLC) with respect to the engagement described herein and supersedes all prior negotiations, representations, warranties, commitments, offers, and agreements (whether oral or written) relating to the subject matter hereof.
Any amendment, modification, or supplement to this Letter must be in writing and signed by both Calderwood & Harkness and the Client. No waiver of any provision of this Letter shall be effective unless set forth in a writing signed by the party against whom enforcement is sought.
We look forward to working with you and your team on this important matter. We believe Calderwood & Harkness is well positioned to deliver the high-quality, efficient legal services that Solara requires in connection with the Reorganization, and we are committed to achieving a successful outcome for the Client.
If the foregoing accurately reflects your understanding of our engagement, please sign and return a copy of this letter to the undersigned at your earliest convenience.
Very truly yours,
CALDERWOOD & HARKNESS LLP
By: ________
Name: Sylvia Hartwell
Title: Partner
Date: ________
AGREED AND ACCEPTED:
SOLARA DIGITAL INFRASTRUCTURE LP
By: Solara Digital Infrastructure GP LLC,
its General Partner
By: ________
Name: Priya Narasimhan
Title: General Counsel
Date: ________
cc: Viktor Raines, Managing Partner & Founder, Solara Digital Infrastructure LP cc: Stefan Dalmqvist, Head of Tax, Solara Digital Infrastructure LP cc: Leonard Cross, Partner, Calderwood & Harkness LLP cc: Robert Jansen, Associate, Calderwood & Harkness LLP
Target Date | Milestone
June 16, 2025 | Completion of initial comprehensive tax analysis memorandum
July 1, 2025 | Circulation of draft PLR Request (Version 1.0) to Client for review
July 15, 2025 | LPAC review of final PLR Request draft
July 22, 2025 | Pre-submission conference with IRS CC:INTL Branch 1
August 15, 2025 | Submission of PLR Request to IRS

CALDERWOOD & HARKNESS LLP Attorneys at Law

CALDERWOOD & HARKNESS LLP

AGREED AND ACCEPTED:

SOLARA DIGITAL INFRASTRUCTURE LP

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