Backpack bone isn't same as vanilla and cause abnormal movement

[Balesheass]

Hello,
vanilla backpacks follow the movement of the spine_fk.005 bone to make it follow the movement of the body armor, I don't know what bones the RHS backpacks use but I assume they are the ones used for the belt, spine_fk.003 or 002, or maybe the spine_fk.004 ?
This causes the backpack movements to slide abnormally on the body armor when the backpack movements should be a consequence of the body armor movement.
I know this is a minor issue but it should be easy to fix, I would be grateful if you do so as this causes an anomaly (still playable) with my custom character animations, I spent a lot of time on these animations made from scrath and made firstly for the amazing RHS, and I will probably continue for a few more months, even if you don't fix it, for free because I fell into this passion.
I am attaching two clips to compare the vanilla BP movement to the RHS.

Desktop.2024.09.12.-.19.06.45.08.mp4

Desktop.2024.09.12.-.19.09.39.12.mp4

[Balesheass]

I attach two clip using my custom anim to show the anomaly i was talking about
First clip vanilla backpack is fine but second is RHS backpack.

Workbench.2024.09.12.-.19.35.59.19.mp4

Workbench.2024.09.12.-.19.34.56.15.mp4