This was one of the ideas backed by the DQMH Trusted Advisors for the next DQMH release (post 5.0 release).
I would like a right-click plugin where I could right-click a DQMH broadcast subVI and "Find Event Frames". This would search all VIs in my current project for event structures that are registered for the broadcast event fired by the subVI I clicked on, and show me a list of results that I could double-click and be shown the event frames one at a time. Or I guess it could just open all the diagrams for me, since I probably want to walk through all of them anyway.
The operation could take a while, but would be worth it. I often find myself wondering where all the places are in my code that are registered for a particular broadcast.