i have 2 commentators together in the same commentary booth, using a laptop with vMix HD and Focusrite Scarlett 8i6 USB Mixer. it has 2 independent headphone outputs with separate level control, and option to direct monitor inputs on the headphones. so no delay hearing themselves.
they are remote so they grab feed using SRT from another vMix workstation and push commentary back again using SRT. they watch on Fullscreen using 2nd laptop HDMI output and have that fed into 2 monitors through a hdmi splitter (DA). so they can distance themselves from each other.

if i was to need to do this more local, i would use NDI instead of SRT to reduce the latency. but it works great.... only issue i have ever had is with the hdmi splitter, but that s hdmi for you, just a digital version of scart...

hope this helps

x422man

With the scarlett 8i6, will each individual input show as a separate input on vMix? And will the scarlett 4i4 (since cheaper) do the job for 2 commentators as per your setup? I need to do setup for 2 commentators

https://www.amazon.de/-/...i4%2Cmi%2C105&sr=1-2