I have a sync setup with Gmail Outlook contacts. This works like a charm with the current Outlook 365. However when I experiment with the "New Outlook" the sync fails and I get an alert that I have a user mismatch. This will cause a problem when the "New Outlook" is the coin of the realm.
I have this issue too.
Unfortunatelly GCSM will not work with new Outlook, which is just a replacement for the old (free) Mail & Calendar apps, which are pre-installed on Windows 11. see also. https://sourceforge.net/p/googlesyncmod/feature-requests/280/