I don't know about other rvs ... my 30 amp cord used to just come out of a hole, there was no plug. I didn't like that idea, so I cut the cord off and put a locking marine 30amp female socket over top the hole.
Like you, I thought I'd like a 90 deg adapter so I can run my generator while driving. Well, I do, but I use the regular straight cord. The adapters add too much weight, and I didn't want that stressing the socket's locking mechanism (just small copper spades)
The adapter sticks out as much as the regular cord does, and it adds weight.
Clicky