I suggest apart from move selected objects to other side to make also move selected objects to a layer. The user would select a layer in the pulldown menu and it would move the selected objects there (only those that can be moved to that layer, so not pads and pins).
I have a groundplane on GND-sldr, a soldering rim on solder side and a small rectangle on solder layer that connects these two. I am unable to move the small rectangle to GND-sldr because GND-sldr is active and when I press 'm' key, it preferences the big rectangle that is already on GND-sldr (because the active layer is being preferences) and never moves the small rectangle. CL<
