The RV builders use some latitude from the NEC although, if they want that RVIA sticker on the outside, all should be according to the NFSC.
I don't see many kitchens in sticks and bricks that have 2 x 20 amp circuits split to a duplex receptacle and have never seen one in an RV. Never seen a 20 amp circuit in a dining area, either. There's probably dozens more that don't agree with NEC.
I'm glad to see the post about how a low battery can affect a converter. There are many posts on the Forum about converters not operating and lights dimming, etc. Maybe this post will alert a few to the relationship between converter and battery.