My wife's ebike motor is a Shimano DU-EP800(RS) which isn't compatible with the new Shimano 12 speed Di2 XT Rear Derailleur (requires EP801 motor). I'm wondering if the new derailleur (and shifter) is entirely incompatible with the EP800 or if just the new FreeShift & AutoShift functions won't work and normal Di2 shifting will work. Her bike currently has a XTR 12 speed mechanical groupset. I'm interested in swapping out the rear derailleur and shifter to the new Di2 12 speed if possible. Any ideas about the extent of the incompatibility or how to find out about it would be appreciated.