The best existing plugin for auto-tagging anything

I’ve tried a few out there, but nothing comes even close to Automatic Post Tagger in terms of interface and features.

– You can define auto-tagging groups for any existing taxonomy (including custom taxonomies and even the less obvious post_format, used by some themes) which is very handy.
– It can match string patterns, which makes it very powerful and efficient.
– The comprehensive settings make it very flexible.
– You can decide to trigger auto-tagging on post with specific type and statuses, on specific events (publishing, update, import, save).
– You can match words in the post title, content, excerpt.
– You can trim the content to be analysed for matches to the first X characters.
– You can append or replace existing terms, or skip posts that already have terms.
– You can limit the number of added terms.
– You can batch tag existing post (with very acute control and tracking). The batch process is fail-safe and soft on server load, even with tens of thousands of posts.
– It works perfectly along with any syndication plugin (I’ve been using it along with FeedWordPress and WPeMatico) allowing you to auto-categorize automatically a very large flow of articles using your own “natural intelligence”!

Automatic Post Tagger hasn’t been updated for the last 5 years but it is still working flawlessly with the latest version of WordPress (5.5.1 as of now).