Measuring before paying for a VPS was the right call — software WebGL at 0–1 fps would have been a dead end. Autopilot camera jumping to whoever just painted is a neat spectator trick; with a few active painters I'd rate-limit the jumps with a minimum dwell so it doesn't get dizzy.
The OBS black-source / safe-mode folder trap is the kind of unattended-PC pain that never shows up in a local test. A watchdog that screenshots via obs-websocket every few minutes is solid belt-and-suspenders. Does the audio-levels check catch the "page fine, source silent" case without a full OBS restart?
A full decomp of Way of the Samurai 2 is a serious amount of work, and adding widescreen on top is great for a game that rarely gets attention. How did you handle the fps unlock? Old PS2 titles often tie physics or animation timing to the frame rate. Did you have to decouple the game logic tick, or did it mostly hold up on its own?