At the moment that doesn’t work out of the box. But indeed it would be pretty nice if someone implemented support for that. I guess one could use the existing WebDAV service as a starting point and adapt that code. One thing that might be a little more tricky is the OAuth handling from within LibreOffice. From what I can see, all existing services only use some kind of username/password combination.
Maybe another approach could be some kind of bridge service that behaves like a WebDAV server and translates the requests to the remoteStorage protocol. That could then also be used for applications other than LibreOffice.