A:Answer While I cannot test other headsets, such as the rift S, I know that the HDMI port is connected directly to the dGPU, and does work for my CV1 Rift.
In addition, in the Nvidia control panel Physx page it shows every port except for the internal display (for optimus) as connected to the dGPU, which should mean that if you get a type C to displayport adapter that it would work for other headsets that require displayport instead of HDMI.
