I make mostly 2 sided boards.
It often happens that the bounds of the traces/rivets on the bottom of the of PCB are not the same as the bounds in the top. When I’m starting a new board, generally by drilling holes on the bottom side, the workflow asks to choose an outline for the board. But position of the circuit on the bottom impacts the position on the top.
So, for example, if there are vías and traces on the lower edge of a PCB on the bottom only, and on the top of the PCB the traces are near the upper edge, it can be difficult to know where to position the board safely when I can only see the bottom circuit.
It would be nice if I could specify both sides of the board, particularly when drilling (the opposite side could be darker/ghosted) so that when positioning the circuit I can see where the traces will be printed on both sides.