Remotely connect to Windows 11 PC using a "passwordless" account
Remotely connecting to a Windows PC with a Microsoft "passwordless" is possible and I finally found a simple workaround at https://cmdrkeene.com/remote-desktop-with-microsoft-account-sign-in/
Copying it here is it does not get lost:
On the PC hosting the remote desktop session (running Windows Pro or better), run the following command, replacing the example email address with your Microsoft Account email address that you use to login to the computer.
runas /u:MicrosoftAccount\firstname.lastname@example.org winver
At this point, you should be able to connect to the remote computer using the same account & password you just used to run the above command. to run the above command.