No, the whole thing is too much like work. The CSS has no license so anyone is free to rip it off and use it - someone who has already set up their lemmy development environment would be able to incorporate this CSS in a few minutes.
Plus I'm sure the devs are frantically dealing with far more important issues to do with scaling, spam and moderation so they won't get to my PR for months. This user script approach gets a result out there immediately.
Also try these https://userstyles.world/search?q=lemmy