1. I tried creating a new book to test copying ACs to an existing work (adding relationship) which works really nicely. However a superfluous empty revision was created in the process:
https://test.bookbrainz.org/revision/30175
Checked in the DB, there is no author_revision, work_revision, etc. for any entity type, which suggests it's an empty revision with no changes. For info, I didn't add any info other than entering name