Honestly, there aren't that many, and you can find all of them with a Quaddicted search:
https://www.quaddicted.com/reviews/?filtered=kell
One you might miss, though, is Remix of the Damned (e1m2quoth), which is part of the Quoth download and not listed as a separate map (and it's a pretty nice map).
Quoth also contains a version of czg and Vondur's remake of e1m1 that has been quoth-ified, as well a bunch of test maps, some of which are effectively full maps but aren't necessarily mindblowing nor have the best balancing, as I recall (been a while since I played them). Not sure which of those were made by Kell.