Linux

You should keep it around, per the Asahi docs themselves, and marcan provides some additional details in this reddit comment as well - it's a little older, but I think it still mostly applies since the firmware update script still runs through macOS.

You could try using diskutil apfs resizeContainer <container ID> minimum (I don't 100% recall if the last argument is actually minimum but using the regular --help should give you the correct one) in macOS to shrink the macOS container to smaller than the Asahi installer typically allows, or use expert mode in the Asahi install script to override the macOS size check, possibly with fewer negative consequences than deleting it outright.

Sorry if you already know all this but I thought I'd add it here just in case!