I use decsyncCC - which can use a folder as a form of DAV - combined with syncthing across devices. This requires no server and works well, the only problem is idk of any good decsyncCC folder-structure parsers that can be accessed as a local DAV service from the desktop.
In theory, existing forum software could implement activitypub and link with lemmy & kbin…
I hope to see fediverse SufficientVelocity and Spacebattles one day ^.^