Vassal was originally made for Advanced Squad Leader. That is the game I have played the most on it. There are modules for nearly all wargames worth playing, but some of the big publishers outside of the wargaming community are more reluctant to allow modules for it.
I just tried Virtual Tabletop in VR, btw. 
Both SteamVR and Rift games work on Quest. I just tried via both wifi with virtual desktop and then with the official Oculus Link cable for a tethered solution.