I don’t think Kubuntu 24.04 had Plasma 6 because it was an LTS release. In Plasma 6.3 they completely reworked the settings page for graphics tablets, and they’ve also changed how fractional scaling works so it should be less blurry (if that was what was making it blurry for you before).

Out of interest, which specific features / functionality is missing at the moment that you would be waiting for?

This isn’t happening for another year or so, there’s time to get styli working

I can’t recommend EndeavourOS to my friends because there’s no app store. Manjaro Plasma comes with Discover.