So I want to just roll it all back to Catalina, but executing a restore from a CCC backup from the backup drive onto the 970 EVO resulted in a copy of my Catalina backup existing along side the newly-upgraded Big Sur installation.
What is the best way to wipe the 970 EVO and restore my CCC backup? I am trying to erase / format the drive in Disk Utility (after booting into Recovery) but it simply won't do anything when I click Erase (with "Samsung 970 EVO" as the name, "Mac OS Extended (Journaled)" as the format, and "GUID Partition Map" as the scheme.
The tree in Disk Utility looks like the following (for the 970 EVO):
Samsung SSD 970 EVO 500GB Media
Container disk4
disk4s5
Samsung EVO 970 - Data
Update
Update - Data
Update
Container disk 3
Reserved
One of the 'Update' volumes contains the Big Sur installation (for some reason it was named 'Updated'?) and then when I tried to restore Catalina from my CCC on a separate SSD it created a second 'Update' volume containing Catalina. And now my drive is full.
Thanks again for any help. This has turned into a bit of a nightmare for me.