Smudge & clean might do the trick, but it could be dirty. The smudge -> clean process might produce additional changes that aren't related to the purpose of your commit. Whitespace in particular could be a problem, especially where there's ambiguity in how it should be used. black isn't as bad because it has stricter rules on whitespace. Still, if you aren't checking style rules before every merge someone using smudge and clean could end up reformatting entire files.

IMO the next next step is, as others have discussed on HN, getting your version control to store and abstract syntax tree. tree-sitter could make this easier nowadays, but I think it'd need more invasive changes in Git than just using the filters.

See this HN thread https://news.ycombinator.com/item?id=28670372