It's a bit of a roundabout solution but I found out you can get past the mandatory Win11 Microsoft account creation on a new computer or install by downgrading to Win10, making a local account there, then just upgrading to Win11 after that. All you need is a Win10 boot iso.

Came across this because I originally downgraded my work laptop from 11 to 10 because I didn't want to use 11, but I just updated it back to 11 for supported software reasons.