On the off chance that anyone else would find this useful:

I just managed to get a #Plextor PX-AV200U digital video converter working on #Debian 12.

It worked after first running "sudo rmmod em28xx; sudo modprobe em28xx card=9" – then I could use it as a source in OBS studio.

Didn't get the audio to work, but I just connected it to the microphone input on the computer instead.