I am trying to clone an armature with another armature, this using the “child of” modifier in some bones, the problem is that when using 2 “child of” in the hand and in the upperarm it ends up deforming the “child of” of the hand.
Child-of acts after inherited transforms (as well as after posed transforms, but that doesn’t matter so much, and you’re probably not posing these bones anyways.) Generally speaking, you don’t want to use it with parented bones. Copy transforms is a better choice. If you want to child-of, copy transforms from something unparented that is a child-of.