So what to do when your backup fails and/or you lose data in your sync area, as happened to me (Fail-safe does not prevent deleted notes. Or: how to re-establish broken sync?)?
Since changing to an empty target deletes notes I wish for a possibilty to set up sync at any point in time. Could be a button named ‘restart sync’ or something like that. Then even if you lose data in the sync area or your backup fails, you still have the local database and can start over.