zt... (zerotier, censored for privacy) and eno1 to the trusted zone eno1 interface) and my laptop (connected remotely, over zt...) only ports 22/tcp, 9993/tcp, 5355/tcp, and 22000/tcp are open. 22000 is syncthing so that could just be upnp at work 

preset=2 in the MangoHud.confMANGOHUD=1 %command% as launch option for games you want mangohud in