I know this isn’t quite Asahi Linux related but you can imagine how few users would do this and not be dual booting OSes. I shrunk my macOS partition down all the way to 64GB, the gave the rest to Asahi.
macOS runs fine with ~52GB of 64 used, though I noticed that Disk Utility didn’t load for a whole minute, but maybe that’s a coincidence? I still use macOS a bit for apps that don’t run in Asahi.
Tell me how well it runs for you if you use it with <100GB of space.