Hey, I tried using the code you mentioned, and for some reason it results in anything i place higher than the first layer actually being LOWER
i made a new room and put in the CONTROL object and a floor and a couple of walls on the first instances layer, then made a new one on top with a few walls, and for some reason all those walls are actually lower than the things on the bottom layer
this even seems to happen even if everything is on the same layer, with the walls always being below where they should be for some reason (just to a lesser extent)