I was thinking to a chamber with a wall with alternated panels changing from portable to non-portable (like inverting a chessboard) after the pression of a button. I've found a way but it's quite complicated and requires a hidden room with lasers etc.
However, i created my maps in a few minutes (plus hours of testing and refining
) while with the hammer I can't even create a floor...

I takes time to learn, but it's worth it.