I would use something Fedora-based. It's just a personal choice from myself, since it's reliable and very up to date. By using a modern distro, you increase the chance your hardware will perform better.

Workstation: uses Gnome, which can utilize the great trackpad
KDE spin: as you wanted KDE
Atomic (preferably uBlue, but Silverblue or Kionite would be great too): my favourite, maybe you could test too. You can install the KDE version first, and if you dislike it, you can rebase easily to the Gnome or whatever version without reinstalling

What maybe won't work is the WiFi and some keyboard things from what I've heart, but you can test it for yourself