Found a blog post that gives a quick overview of how to do git via email in general: https://peter.eisentraut.org/blog/2023/05/09/how-to-submit-a-patch-by-email-2023-edition
So at least from my understanding you’d make your changes, email the contents of the patch to the maintainer, and then they’d apply it on their side, do code review, email you comments, etc. until it was in an acceptable state.
There’s also the full kernel development wiki that goes into all the specifics: https://www.kernel.org/doc/html/v4.16/process/howto.html
(I never got through the whole thing)
I know for me, at least with gnome, toggling between performance, balanced, and battery saver modes dramatically changes my battery life on Ubuntu, so I have to toggle it manually to not drain my battery life if it’s mostly sitting there. I don’t know if Mint is the same, but just throwing out the “obvious” for anyone else running Linux on a laptop.