The only issue I see with the HCD as a backdrop is that its going to need to be cut down, as its a center divider. I dont think I want it to go end to end on the layout. If I did that, I would have to cut out slots so the door can come down over the tracks and the trains can get through. Not sure if that would make it weaker. But if it sits in a slot in the 2" foam, and even screwed with small L brackets to the base, I dont see that being an issue.