Now that we’ve switched to LTX, this isn’t a problem any more. It should thus be possible to replicate /data/*.db, even if there’s hundreds or thousands of databases in that directory.

That was the show stopper. Now multi tenant with per tenant database whee (in theory) each user can roll back to certain point in time or at least completely download their database and take away for whatever they want to do with it is going to be possible.