Interesting prototype start.
Took me a while to understand what I could do besides rotate the room and after that I thought I had no influence over where to place items as they seemed to appear randomly.
But I think there is a bug with the RayCast(?) that determines where to place an item. It only seems to work correctly in one room rotation.
Saw in other comments that you have pre visualization on the list and I agree this would be a good addition :)