Downgrading / reverting to a lower version

We should likely speak of “database” in the plural, which also begs the question of how to tell what was what, even to the extent of distinguishing former Duplicati-server.sqlite from former database for some backup job.

How to test which database belongs to which job? gets into this, but the solutions discussed are rather crude even before getting into Windows database encryption (I wonder if backups follow --unencrypted-database?).