Update: On my RV Building Plans....

You have perviously posted that you plan on using a RV builder to help you complete this project. From the 2+ years that I have been on this forum....one thing pretty much universally stands out, most if not all RV's on the market are cheap thrown together crapola unless it's a mega expensive 5th wheel or custom bus.
It seems like you have a pretty good plan so possibly you should expand your builders to outside the RV trade?

Thanks for the update. Another suggestion - take photographs or have the builder do it as the build progresses. Knowing exactly where the framing is located and where the electric and plumbing run will make future changes and additions much easier.