Only one PowerWall is currently connected. They did not have all the breakers on hand that they needed. The AFCI breaker for the relocated bedroom circuit is also missing, so it is still connected in the main panel. The Enphase micro-inverters are still happily talking over powerline to the Envoy even though the power is going back to the main panel through the Tesla Gateway to that one AFCI breaker that needs to be relocated.
Progress!
Question: I'm only seeing two double pole breakers in the new panel, based on your description I expected to see two for PV plus one for PW (soon to be two, four total).
Powerline communication can't cross a transformer, other than that any conductive topology is good.