DAV is challenging and of limited utility in a shared system, unfortunately, as it runs under Apache, and doesn’t work well with files owned by the domain user:group. At least, that’s how it was the last time I tinkered with it.
There are alternative DAV servers, as well, but I haven’t looked into it in a long time, as it just doesn’t come up very often as being a thing people care about. DAV was a mostly failed protocol (it’s not a great protocol, and doesn’t satisfy the common use cases very well). I thought it’d be a more popular feature in the past, but then I actually tried using it, and found it’s not a great network filesystem (where network filesystems are things like NFS or ceph or SMB) and it’s not a great file transfer tool (where fil transfer tools are things like like FTP/scp/sftp) I stopped paying attention to it.
It’s possible that mod_itk will allow it to work for user-owned files without having to us too-loose permissions for safety, but it’s also not something I’ve looked into. It’s plausible we’ll support mod_itk in the future, but for now, that’d be something you’d need to setup on your own.