For what it’s worth, this is the quickest way I found to discover what’s been successfully autotagged, short of writing python scripts.
Since filtering only has a predicate for “tag” and not “autotag”, filtering is not an option for discovering autotagged items (please correct me if I’m wrong on that). The only way to do that is by using search. Any autotag matches typed in the search box will be displayed in a search results section called “Automatic Tags” as shown here:
So, in the search box type in something common like dog/person/tree etc. It will display any matching autotags in the autotag section. I was able to drill down and scope out what’s been autotagged quickly without writing any scripts, messing with export dumps, or going at the sqlite db.