Canonical kernel dev here. I believe most are on Ubuntu as we test regularly on our machines. Some are on 22.04, some working on more development kernels are likely using 23.04 or even Mantic. There’s probably a few still on 20.04.
Thanks for the answer, I was really curious about this.
Nicely done.
What do you folks think of Mint? I'm a big Ubuntu Mate fan BTW.