so it's done through custom code, checking for the Unity OnCollisionEnter and OnCollisionExit events on the targeted rigidbodies (vr hands fingers) with any other rigid bodies and filtering them if they're not of interest (targeted areas of the body of the person atom that has the plugin) more exactly. I don't think you can with vanilla vam if you're looking for something like that except if you hardcode collision triggers all over the body yourself, that should work fine but might drive you crazy in the process
I didn't try your scene yet, i'll check it out, but I did check the .var and noticed no /scripts so with vanilla vam probably that's the route you took with collision triggers, I thought about something like that too a while ago in my vam crazy machinery phase. If so, in theory your approach should work fine too
People over at my patreon actually voted for something like that to be the next release and it should be coming at the end of the week. It's gonna be a separate plugin, ExtraTriggers, and it's actually gonna work with any atom parts colliding with any other atoms parts. i rambled about it a bit over there over the weekend and posted an early wip if you want to check it out