Live in the Keys and watching as well.
Just thinking about the complexity of adding a second AC:
- Cutting through the roof in an area that has enough existing structural support and making sure the install does not leak
- Running the wiring and ensuring that the coach has enough extra electrical capacity to run a second AC in tandem with the original AC along with other electrical draws. Hopefully the coach is already wired for 50 amps with a energy monitoring system to shut down loads (frig, water heater, etc) when those compressors are starting up. I don't think 30 amps can handle it.
- Will existing generator handle additional AC load?
This guy on YouTube has a unique approach by using his existing vent hole and running a whole separate plug to feed the 2nd AC outside of the RV wiring.
Good luck and keep us posted on how you make out!