I notice that the Steam version supports Union mod and ZGamePad, but when I install the GOG version of Gothic 2 Gold, it keeps loading the Virtual File and the ZGamePad plugin not working (even when I have DS4Windows on with a Dualsense).

Never mind.
I got it working now with Spine Mod Manager.
Thanks god.

EDIT: I got it working without Spine even, turn out I miss out the part where you are supposed to apply the Primary Universal patch first before installing Union.

Now ZGamePad works like a dream.

It's sad as hell, but I think the Steam version of Gothic 2 is easier to deal with than GOG's Gothic 2, damn.