As for door to door we are usually on almost empty Aires and never campsites.
We have no problem with our hab door being on RH side even in UK, but we do not have grandchidren - well not in the MH.
I think it would be impractical for continental converters to offer hab doors on the LH side for the limited UK market that never wants to leave UK. Then when those owners wanted to sell to people that are used to touring Europe they are disadvantaged.
There is no answer for the continental converters.