A few of my snakes have hides in the racks. One will refuse to eat if she doesn't have her hide woobie, although it's a cereal bowl and she's an adult breeder size female now. (she won't accept a larger one either, only that one).

If the snakes don't stress over the new additions, then the only detriment I could see would be cleaning all of it on a regular basis. So a bit more work for you.

I wouldn't think that fatty liver comes from lack of exercise as much as overfeeding(especially powerfeeding to get animals to size quicker). But voluntary exercise can't be bad, right? If the python doesn't want to slither about, he can sit in one of the hides.