The previous owner of my 3400RL removed the generator from under the front bedroom area, so there is a bit of room in there for the outdoor unit. Since the bedroom is where I'd consider putting it, this would be fairly easy and avoid many of the issues others are dealing with. I've used mini-splits for years overseas but have yet to see one sized for an RV. Suspect that a micro mini-split would be in order, such as these:
https://tinyhousehugeideas.com/small...-conditioners/ . The top pick is a Pioneer at about $900 with these specs: Type: Cools & Heats
SEER 19.5
10 HSPF
Indoor Size: 28.5 x 7.5 x 11.5
Outdoor Size: 30.5 x 12 x 22
Room Size: 200-350 ft2
I do not see Samsung, Mitsubishi, or LG listed as manufacturers of these micro units. They start at around 9000 BTUs, which is the probably the low end of most requirements. Given my one AC unit at the opposite end of the RV, I think one of these micros would probably suffice. I am not going to get into the roof mount vs. wall mount issue since that will be peculiar to each owner.