Similar questions have been asked, but the rules kind of points that something like this should be fine.
I have a library that is essential for all my projects, it solves data and event dependency spaghetti code.
It doesn't provide any gameplay functionallity, only gives quality of life tools that makes it easier to write code. (It's also open source)
The rules specify
Asset store assets are not allowed either, except for the ones that don't contribute to the game itself but make the workflow easier.
By reading the rules, only asset store workflow libraries are allowed, not self made.
Meaning, by the rules I can not do this, it feels like a flaw in the rules.