There are already some mods which allow you to layer elements easily.
For eg try this one https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=23002
Up. But for the record, layering is a niche feature; it's barely supported (just kinda works) and likely won't be supported to a greater extent in the future either. The things you refer to as "different layers" don't actually exist; instead, the order particles are rendered (and thus seem to be ordered along the Z axis, or how far away they are from you, kinda) depends on their ID. Since the particle ID is a concept even more technical than layering, any feature that operates directly with IDs is an even more niche feature than layering.
I find it difficult to name the problem specifically so that you can understand, so I will sign it. I copy part (using CTRL + C). then after working with this part, I want to turn it (I use R), everything works, only the part turns a little to the right (1 cell) it really hinders (I think everyone), and I would like you to fix it, it's not difficult, but I For this, the ad blocker turned off :)
Placing and rotating stamps work on the 4x4 grid that walls are placed on. To nudge your selection, use the arrow keys.