If you drag right-to-left to select modules the delete command doesn’t work.
Right you are although I find it very weird to be doing it from right to left! ;)
Also when dragging from right to left the first module doesn’t get highlighted which makes me think that probably the option shouldn’t even be there.
While we're at it, it would be great if while selecting from left to right, when reaching the right border, the rack would be scrolled slowly (no dynamic speed please) to continue the selection.
Copying racks in parts will destroy multiple connections that can be quite hard to re-connect.