That’s not a final fix yet but a starting point. The next step is to normalize the signal step-by-step to get an idea of minimum number of hacks needed for a compatibility mode option. I just corrected hsync-vsync alignment and re-uploaded to the same file – can you try if it still works with PSX?
Ps1 and ps2 start to get a picture once v.active is 297 and higher.
Was that with default V.backporch (19) or with adjusted one (16)?