Best practice for applying minor bone tweaks to all animations in a pack?

[HolSyn_Games]

I have a character who uses retargeted animations from a pack. I’ve made small tweaks to the hand / fingers / weapon bones to get them to hold the weapon properly. What is the best practices for carrying over these little changes to all other animations in that same pack? I’ve looked into poses and additive and layered blends but nothing is achieving that seemingly simple result. Which, I’m sure it’s just something I’m missing or doing wrong but was hoping someone could point me in the right direction!

For reference:
Animation with changes made (an idle to throwing start animation)

Just the idle animation, bones unchanged

basically need ALL of the animations from the same packs to have those same bone transforms applied en masse.

[56legion]

It looks to me that the weapon is attached to the wrong socket.
Utilize the socket on the right hand instead.

[HolSyn_Games]

I wish it was that simple but no - same socket, only thing that is different is the bones on the correct one were aligned for it to fit and then keyed and applied… I need those same transformations to apply skeleton wide for THIS animation pack, and then maybe other transforms applied to other packs.