Maybe you're right. But remember, the SQ lens is triggered mechanically and then held open electronically, before closing mechanically when the power to it is cut. At 1/500 it is opened and closed mechanically, without the body timing it at all. So if all it takes to open a GX lens is to send power to a contact, and to close it, for power to that same contact to be cut, it should work fine off the SQ body, up to a 250th.
The GX lens would of course cover 6x6 easily, as it is meant for 6x8.