Exactly what was needed

Revisions can sometimes be handy to have around when you’re working on a post, but after 90 days, like the plugin suggests, it’s pointless to keep them cluttering up things.

Not sure if it’s been fixed, but WordPress did have a bug, too, that wouldn’t correctly preview posts after they were published if the revision number was set to zero. — Modifying a published post and previewing it meant changing the number of revisions to greater than zero or re-publishing it over and over until everything was right.

This plugin lets revisions be created, but automatically deletes old drafts. Thanks for creating it!