Better home for filterPostie.php?

I have some fairly complex logic in wp-content/filterPostie.php, which I created some years ago.

Problem is: I completely forgot about it! And that file located in wp-content is an unusual location, which doesn’t really jump out at you, when trying to figure why Postie is behaving as it is.

The concept of filterPostie really belongs in a hook/filter, doesn’t it? I realize that having it in this file location makes implementation much easier for noobies – but I spent hours trying to figure out what was going on, until I re-read the entire documentation in desparation.

Perhaps it could be in that file OR as a filter/hook? Just a suggestion.