The AFCI thing is a slam dunk. You need them everywhere but the kitchen and bath.
I don't see the code changing much. They still do the same amount of living. I can see them having enough appliance load for 2 20a circuits in the kitchen. You still have those hair dryers in the bathroom. The laundry circuit might be silly if there isn't room for a stackable. You may only end up with 1 or 2 general lighting circuits and that second one might be just to be polite. You get 600 sq/ft from a 15a. The way the walls are broken up you are going to end up with a a bunch of receptacles tho, even on the really tiny ones. At a certain point I think the designer will have to have a good plan. Since these are factory built and some are not even HUD certified as a dwelling they may get a whole different set of rules. They may be RVs. My SIL had one of those. Once they took the wheels off it looked like a manufactured home but it was built and listed as an RV. I hope someone closed that loophole.
