Webdav Multiuser

What you could do is this, i.e. use the username as the directory to set as root:

route /dav* {
	rewrite /dav /dav/
	basicauth {
		bob <password>
		alice <password>
	}

	root * /home/webdav/{http.auth.user.id}

	webdav {
		prefix /dav
	}
}