Split Controller Build help

I have bad wrist issues/carpal tunnel and want to build a split controller kind of like this one for my xbox one S. The video described below shows it done for an xbox 360 controller, but I need a bit more hlep/info on the wiring/soldering.

*I can’t attach a video link, so if you search youtube for the following, you’ll see what I’m describing:
video title: XBOX 360 Controllers You Can Split!
by element14presents

For example, can I just solder a wire directly between the back side of the board where the B button hits on the “passive/secondary” controller to the same spot on the “primary/main” controller and the main controller will think that I’m hitting the B button on that?

I tried to use the co-pilot mode instead, but it doesn’t want to work for Elden Ring (which I’m playing w/ my son and is pretty much the only reason I’m using the xbox).

Thanks for any tips/advice. If you have any wiring resources that you think would be helpful, that would be appreciated, too.