Feature request, I don't know if it's possible or easy. It would be occasionally nice to detach a block along a plane, rather than a full detach of all sides.

For instance if you wanted to split a linear grid into two pieces, not three, by cutting along the left side of a block, without having to build temporary scaffolding.

There'd have to be some visual indication of which plane is getting detached and some controls - maybe activate it with the block rotation keys.