I have the X1 Carbon Gen9 and I've used Arch as my daily driver for over 15 years I think it is now. Just want to mention in case it piqued your interest that I

I have the X1 Carbon Gen9 and I've used Arch as my daily driver for over 15 years I think it is now. Just want to mention in case it piqued your interest that I recently moved from Arch to NixOS on my X1C9 to help bake my whole system into a set of functional configs. It's particularly nice that I was able to functionally describe my whole system including packages, quirks, patches, configs (system + dotfiles) in a reproducible way. Also I think you'll love the machine - it's certainly my favorite Linux laptop.