Should I use a Catalina Time Machine backup (from MBP) to Migrate data to a Mac Mini(M1) running Big Sur OR should I upgrade MBP to Big Sur and make a new Time machine back up then migrate data to Mac mini?
MacBook Pro 15″, macOS 10.15
You can do either. Time Machine can be connected to the M1 during setup.
I did a migration using Migration Assistant from a Catalina Mac to the Big Sur using a Thunderbolt cable.
Wireless did not work for the M1 data migration.
Migrating from the Catalina TM to the new Mac Mini will work just fine. It will move all of your user data and settings into Big Sur, which is far less time consuming than your second method.
Agree. Works with cable but not wirelessly.
Catalina TM Backup to New Mac mini running Big Sur
