I like the org-agenda-set-restriction-lock feature, but I recently wasted quite a bit of time troubleshooting my agenda views, only to find out that I'd set the restriction lock to a single file.
Is there an option to toggle that would show me that I have
the agenda restricted to a single file? The only visible notifier that I found was on the "Agenda->Agenda Files" menu, where it said "Restricted to a single File".