I saw someone showing off a similar idea with a PS4 controller and I wanted to make one for my Xbox One controller and didnt see any available models so here we are! I have mine fixed to the underside via a strong adhesive pad but I did include two screw holes with recessed edge for a more solid mount.

The analog stick channels are designed so that when the controller is inserted and pushed the whole way back, it will sit nice and straight.

Screw Mount size is M4 or 4mm diameter with a 3mm recess.