I noticed that the Scrum-of-Scrums project workboard has columns for each of the #blocked-on-{team} tags.
The current workboard doesn't seem very useful or convenient since the columns won't automatically get updated with tasks tagged as blocked-on-{team}.
If we migrate the blocked-on-{team} tags to milestones under Scrum-of-Scrums then those workboard columns would be kept in sync with the state of the blocked-on-{team} milestones and we could easily see who's blocking who.