Okay, apparently I am very stupid, so all you have to do is use lighting front back and top in the scene (aimed at the green man) to reduce the shadows, then in Virtual Desktop is bump up the "Similarity" to something like 40%, and "Smoothness" to 0, also make sure not to use any greens in your scenes, and voila, fully invisible posessable male, works great with vamx.
Even better is set your vr hands to be invisible but use collision, and enable hand tracking with the quest 3, use an object like a pillowcase where the girl is, and it's like you're grabbing the actual person with your own hands, which is a really strange sensation.
The one thing that is annoying though and I'm trying to solve, is in vamx the male will stick out his tongue automatically when you possess him, and disabling it in the menu thing doesn't seem to work for me.. Also the girls move too easily when you touch them, like they weigh nothing, I don't know how to add more mass to it or more resistance or something.. If anyone happens to know I'd appreciate it
I also wish VD would add full finger tracking soon like the ALXR/ALVR nightly build does
Edit: for better results and better fps, instead of placing several angles of lights, just go into overal scene settings, scene lighting, and up the global illumination a tiny bit, and the green man should disappear completely