Can the CxA be involved in the thermal model of EAp2?

There was a thread on another product that would seem to apply to your question. Ward Miller provided the results of a CIR related to the engineer that did bridging documents to be the EAc3 Enhanced CxA in a thread under CS-2009 EAp1 (and I am not smart enough to provide an easy link). While not exactly your situation, and while this has so far has not been moved to LEED Interpretation status, it does give a view into how the GBCI is seeing this issue. "The project in question is a greater than 500,000 square feet, multi-building “design and build” project and is asking whether the A&E firm, who is only responsible for the conceptual design of the project, qualifies for the commissioning authority (CxA) for EAp1 (Fundamental Commissioning) and EAc3 (Enhance Commissioning). Please note, since the A&E firm has schematic design responsibilities for this project, for example, the drawings and written specifications required for RFP documentation and for the issuance of the building permit ["they are NOT the engineer of record" that will be shown on the "as built"] as described does not qualify for a “disinterested” party. “Disinterested” means the party has no project responsibilities other than commissioning. For projects larger than 50,000 square feet, the individual serving as the CxA on a LEED project must be independent of the project’s design and construction teams. Note that the LEED Reference Guide for Green Building Design and Construction, 2009 Edition (Updated June 2010), EAp1 Section 5 Table 2, Commissioning Authority Qualifications, has clearly defined the requirements for the CxA qualifications. The employee of the A&E firm who are responsible for the conceptual design of the project do not qualify for the CxA for both fundamental commissioning and enhanced commissioning tasks. If the commissioning tasks will be completed by “disinterested” employee of the firm, who do not have design responsibilities for this project, the individuals qualify for the CxA for fundamental commissioning tasks. Therefore, in this case, the project is eligible for EAp1 but not for EAc3." So, based on the above, I think that someone doing the energy model would be part of the design process, and would not be able to provide Enhanced Commissioning. Now, that is my opinion, and you could get a CIR on the topic. There are LIs from v2.2 that have said that the LEED Consultant on a project could be the CxA, so I would assume that is valid for v2009 as well.