The peer_workflow_item.author.submission_uuid is a litte more complicated than I would like, but it is all indexed foreign key lookups so it should be relatively inexpensive. 

I was playing around with select_related and reading some documentation around it; looks really useful, but I'm not sure if it would work in this circumstance. ManyToMany relationships in particular seem not to work, and I think you have to call select_related from the table itself, not a sub query. 

I'd like to play around with this though, and len(db.connections.queries) might be nice, along with some other measures, to ensure we don't get extremely complex; we should discuss this as a quick secondary PR.