Oh! I got confused there, I thought GCHD and OBS were supposed to be settings for the Cam Link. That’ll teach me to browse the forum while I’m sleep deprived 😛 OBS actually has an interesting page on what these settings do. Since I use both a Windows 10 PC and a MacBook Pro (for “in the field” captures) with this device, “Auto” seems to be the best for me. Some initial weirdness might well be explained by the fact that I am supposed to start up GCHD, leave it running for 10 seconds, then shut it down again to update the Transfer Mode setting.
Note I only briefly tried out OBS, but it didn’t seem to be able to do anything that GCHD doesn’t already. Other than for stability, is there a reason to use it?