I've been seeing what I think are pretty consistent multiplayer ball tracking bugs, such as only two balls or no balls being launched for hellevator, or the ball ending immediately after stacking hellevator with a mode after draining the ball in play before the others are kicked out.
These might also be attributable to trough power issues, but they seem to crop up much, much more frequently when playing four player games.
If also like an option to disable the ghost loop opto and drop bank and compensation for a non- working opto or drop servo.