Hector Martin on Nostr: In my case, since I *could* actually dump the data, my searches led me to people ...

In my case, since I *could* actually dump the data, my searches led me to people talking about third-party backup/restore of macOS, and eventually somewhere someone had documented how to recreate all the APFS volumes and run all the magic commands to make the new OS bootable again (and how to copy the data without losing stuff like resource forks and xattrs).

Even then there was some loss, I remember I lost the Finder "is a bundle" bit and, although that is mostly obsolete and replaced by plist magic inside the bundle dir, it mattered for some VSTs (!) that stopped working as a result.