Originally Posted by
Trakhak
Won't work. The first time you applied backpedaling force, the lower run of the chain would assume a straight line, stretching both the rear derailleur body and its cage fully forward (and very probably breaking it). Meanwhile, the upper run of the chain would go slack, drag on the bottom of the front derailleur cage, and likely run off the rear sprocket.
Thanks for that. This is why I reality check any crazy ideas, particularly when I can't find someone else who has done them in the past.