I just managed to get my old mac updated to big sur and apparently I can run it. I downloaded cooking mama as a test and it looks like a regular mac app running a unity game lol. idk where any sort of drm/login check is happening. I'll have to experiment further. should be easy enough though to download the .app and back it up onto an external drive so mac doesn't auto-delete it (idk if it does that). it might be the case that it just logs in upon boot, and if that's what's going on, theoretically it should be easy enough to just swap the launcher with something that doesn't rely on apple login?

I'm not an expert in cracking games but I do a lot of RE work. now that I got my mac setup for it, I'll definitely take a look when it releases.