Same idea goes for other elements for example: Helmets, Clothes, Armor and other parts that I can customize ABOVE the BASE character, all animated frame by frame on a dedicated transparent layer of course.
Wow, give me some of that dedication!
Anyway regarding the desyncing... are you 100% certain that all values are the same and stay the same? It would just be the obvious thing that you have overlooked a value somewhere.
If that´s not the case, you could set all equipment having an animation speed of 0, then do something like
That should work.