I just received the new KH rail adapter for the KH24 Signature series uni and it’s great. Being able to tilt the saddle for comfort is a real pleasure. I have the tilt maxed and just got back from a short Muni ride and found I like it that way.
I was lucky and got one early (maybe the first). They might be available now at unicycle.com but they’re not yet on the website. Here’s a couple of pics.