Seismic, I see on your pictures you are not using a pot on your roll.
I use a gimbal with a similar design as yours. Modifying my savox servo and adding a 1 turn 5k pot to the pitch made a huge difference, but I cannot find a similar pot for the roll.
Mechanical limits in my gimbals roll are aprox 70º, so I need a 5K POT with 1/5 turn, did anybody find some of these?
The most similar thing I have found are the original cinestar roll pots but they are not exactly cheap....