CxA Same for all Paths?

No there should be a lead Cx Authority but the building envelope Cx can be another person that meets the qualifications. The qualification for Cx is spelled out in the Reference Guide.

First off, the energy systems CxA and envelope CxA do not have to be the same company, and in many ways should not be. The expertise for envelope is quite different than for systems.

But I think there is a little more nuance to your questions...perhaps. Option 1 and 2 are distinct. You can pursue both or one of them. You can only do Option 2 if you want. While it is clear that the prerequisite and enhanced commissioning for the energy using systems must have a lead Cx Authority. But there is little guidance related to any relationship between the energy systems and envelope firms.

I have gotten to work closely with envelope commissioning, and we always coordinate and assist them (often there are things in the mechanical systems that we need to do to help with testing). But as I have mentioned before in my answers, good envelope commissioning is heavily weighted toward design review, shop drawing review, and installation review. The tests are a final check, but are not the focus. Energy systems have a good portion of value in the peer review, but the maximum value is in the functional testing and action item resolution.

Sorry, one more comment. Path 2 is really an additional service for the energy systems work of Option 1, Path 1 (the first line of Path 2 is to do Path 1). That should definitely be the same firm as Path 1.