What if there was a tool, that when activated would put your "ghost brick" into subtraction mode. for example, if I have a 6x6 plate laying on the bedroom floor and i position a 2x2 (ghost) plate in the center and try to plant it, it would simply "subtract" from the 6x6 and instead make 2 2x6's and 2 2x2's.
I hope that wasn't to hard to understand, but this would be a great tool for poking holes in roofs and such..
