Not related at all to planning/outline tasks, but once you’re actually writing your work –
IMHO, Scrivener’s Word Frequency tool under Project Statistics is a great idea with a not-so-great implementation, at least in Windows. There have been a few threads on how it could use some improvements.
Seems to me developing an improved Word Frequency analysis tool would be a perfect application for a Python project. In fact, the poster of this 2023 thread planned to do just that, and provided their outline for doing so. (No idea if they actually implemented it or not.)
Best,
Jim