the latest Windows10 version seems to have broken compatibility with my Startech PEXHDCAP60L unfortunately, as I said previously I can only use driver version 143 or below as anything newer won't give me any picture even though it says there is a signal in the video control panel, but now I get sporadic bluescreens whenever I try to use the capture card 🙁 can get quite annoying.
so I had to do a makeshift solution for now, took out an Extron RGB-HDMI 300A and use a HDMI capture card instead... played around for hours with the settings until I got a result I'm happy with, but it's surprisingly good now, unfortunately it's not as fun to play through the capture window like this as this introduced double latency from the capture card and the scaler, with the PEXHDCAP60L there was barely any latency noticable, so I could even play fast paced games directly from the capture on my main PC.
I thought I'd share anyways what results you can get from the Extron if you spend enough time tinkering with the settings... I set the scaled output to an integer multiple of 320x200 (1440x1000) and adjusted the input signal so the pixels would align as best as possible, then I downsampled the resulting picture in OBS into 320x200 to get rid of any filtering artefacts and scaled it back up to 4:3... I have to readjust it sometimes to make the pixels line up perfectly again but the results are quite good.
the Extron has the advantage at least that it doesn't freak out on changing resolutions like my capture card ^^ but then again, my current setup only works well for 320x200, I'll have to do custom setups for other resolutions in the future, but you can conveniently save presets on the scaler itself.