Similarly, I've been wanting to make an autoformatter that reorders CSS properties into these categories: https://9elements.com/css-rule-order/ (box model, positioning, typography, etc)

I think it's the most useful CSS organization method I've found yet.

You might be interested in https://github.com/hudochenkov/stylelint-order

This is what I've always done naturally for the 20+ years I've been writing CSS. The only difference is that I put animation at the end, probably because it came much later than the rest.

Yeah, it really helps out, and I just head each section with a comment for fast grepping and grokking. My system combines a lot of things into the Display category which could be split out but I think I've struck a good enough balance.