I concur with the other commenters... I've been syncing with dropbox for years now and never had a conflict. I guess it helps I tend not to leave it open/running on multiple machines. Open it, use it, close it.

> At the very least, a .kdbx on Syncthing/Droxbox-like storage WILL eventually lead to data loss.

It's been working for me without issue since 2009-ish. I've used 1.x and 2.x databases in Dropbox.

AFAK if a conflict occure, it will create a "conflicted copy" of the kdbx file. You still have to merge files manually but no data will be lost in the process.

This is correct--I've had conflicts and a second kdbx file is created with conflicted copy and the date of the conflict in the filename.

It's a small pain to go through and figure out which item is out of sync, but doable.

At some point new passwords will be added quite rarely. Clash can happen, but in practice I've been happily using this method now for years and years.

Keepass will let you merge the databases if a conflict happens.