https://github.com/metabrainz/musicbrainz-server/blob/master/root/components/tags.tt (and its React version) does basically the same as https://github.com/metabrainz/musicbrainz-server/blob/master/root/static/scripts/common/components/TagEditor.js#L426 but for logged out users. It would make sense for us to merge the two, and just have TagEditor not show editing bits if there's no logged in user.