I have a few work arounds to suggest. I use apartment type buildings in other worlds, but they’re designated residential. I just make sure beds are set for specific sims and doors are locked to anyone but the household. It plays close enough to an apartment for my needs.
If you want to have Mt. Komorebi just as a resort, you can designate all of the residential lots as rentals. That will keep the game from moving randoms in. It won’t change where it displays on the world map, but it’s functionally a resort town. I’m actually the opposite of you on this one. I want the destination worlds switched to residential. With the ability to create rentals anywhere, now, I think having only destination worlds is a waste of real estate.