I’ve tried install the nextcloud command line client, which pulls in alot of gui packages and if really heavyweight.
Is there a mightweight version for the command-line version which could be used with success on smaller devices?
Will (any client) it sync both ways?
No WebDAV by itself is an file access, but not a file sync protocol. But there seem to be lightweight options that also allow syncing through it.
Sorry bit unless you’re not telling us anything about your use case it will be difficult to provide more detailed answers 