pressing the “Onion skin” button or the corresponding keybind will create a transparent copy of the current frame your last selected rig is on, and it shouldn’t interfere with your undo history or your ability to select any parts in the animation editor. it does require the rig to be listed under RBX_ANIMSAVES though
after receiving a few scathing reviews i updated the plugin a bit, it now has two (2) dedicated toolbar buttons, one to create the onion skin and one to clear it, so u dont technically need to set the shortcuts anymore and u can just use the buttons
also it creates a hidden humanoid to give the parts a bevel, and i made it detect the head mesh (if a mesh inside the head uses the head meshtype) so the onion skin itself looks a little more accurate to the rig
and i removed the arbitrary restriction of requiring the rig to be listed under RBX_ANIMSAVES in serverstorage, instead it just looks for a selected model + humanoid sow that might make it less clunky?