I’ve been following an interesting project that uses a Raspberry Pi Zero to convert RGB from classic consoles into HDMI with only 3ms latency added…which is so low, it can be considered “pretty much zero”. Unfortunately, this project won’t work with consoles, only older, low resolution PC’s.
Using a Raspberry Pi as a scaler has so much potential, as the RPi4’s can go up to 4K and potentially add scanlines that are more accurate to a CRT’s mask. Unfortunately the main developer says they’re only supporting the PiZero and any console (or computer) with too many discrete colors is too complicated to be supported.
The project is open source, so hopefully this is something that can evolve a bit more. In my opinion, even if there’s just a small chance that this method would work with consoles, it’s worth looking into; Imagine buying a Pi4 and a “SCART input hat”, then loading some software and having a 4K scaler?