It would be very nice to get a compatibility list going including compatibility with all output modes of the OSSC. I have a only one capture device which is the external Elgato HD60s. I have had success getting it to work with RGB signal from my SNES and 2x scale output but it does not like 3x, 4x or 5x.. I’m going to do some testing with other consoles and other inputs as well like to see how it handles the Gamecube 480p signals and scaling from OSSC. I have an acceptable streaming / youtube setup for SNES and I assume other 240p RGB signals using this cap device and a BenQ 32inch 1080p console gaming monitor that has 0-1ms input lag so pretty much nothing. It is as close to a CRT as I can imagine. In 2x the monitor displayed the game stretched but I was able to find some settings in the BenQ like overscan, aspect 4:3, and a smart scaling feature that let me blow up the image to roughly fill the vertical part of my screen. Captured video looks quite good as well.
It would be awesome to find a capture card/box that was not picky at all about OSSC output and just captured it all, but that may be asking a bit too much.