Hi JACK,
EXCELLENT! PROBLEM SOLVED. HERE’S HOW IT WENT,
steps 1==> 2 - Spinning loose was nice... but did not finish... Error code 5101F
Step 3===>11 - Erase went OK... some of the options were not available.
Step 12===>13 - The install macOS went ok. Maybe the install app does some clean up needed, but bypassed by the Disk Utility restore option?
Step 14 --- With the new APFS secret partitions, the restore user part of the set up function did not have enough free space to proceed. I eliminated the biggest part of the user merge (Pictures which was HUGE!) and the migrate/restore user of the new macOS set up function worked fine. I made a copy of the original source Pictures folder, made an alias of the file <iPhoto Library.photoslibrary> and moved that to the target user folder. Total success. Nothing lost.
I like the separation of the Apple applications (In the System.Applications folder and putting the non-Apple applications in the traditional Application folder. Hope you can similarly isolate the extensions Apple/Non-Apple. It would have made my initial attempts to eliminate the old/un-updated Apps/Extensions that were infecting my wife’s computer. Turns out, none of them were currently needed for her main line work
Many thanks