Maybe I'm learning too late obviously. The so it looks like I have two issue per your diagram.
1. I do not have the RV ATS as shown, the only ATS is in the inverter.
2. I also would need a sub panel and rewiring of other outlets I want to run of the inverter.
I also don't see a converter in your drawing where in the diagram would that be?
I thought guy I hired knew his stuff but I guess not.