In an ideal world, this box will be plug-and-play with the Taito F3 + OSSC combo (or certain other problem PCB / capture card / monitor combos), which, pretty sure, won't work without further sync processing. Both
@RGB and
@invzim seem to have this figured out in the latest reversions of the HAS and Tri-Sync Helper, so you might want to ping them about sync handling. Putting in a more modern HD-compatible C-sync -> HV-sync converter like the Renesas ISL59885 may be all that's needed?
Any downside to making the in-cabinet HD15/DE15 fixed HV-sync if it fixes things like the F3? Every user for this would be a tri-sync CRT or flat panel, I'd imagine.
How about making the second A/V output on this for capture and/or VS cabinet use? I'm thinking VS cabinet style 1-into-2 VGA + RCA. Basically every non-Framemeister/RetroTINK scaler somebody would want to use in 2021 supports VGA input and there's plenty of VGA capture options from Startech/Micomsoft (read: Yuan), Datapath, Magewell, etc. Those RetroTINK, Micomsoft, and DVDO scalers are limited to a 4:2:2 color pipeline anyways.
I get the appeal of using a Genesis/MD-style A/V connector, but those Genesis to YPbPr cables from HD Retrovision / Retro Gaming Cables run ~$65 USD/ea and only come in 6'/2m form.