@roomey The only list I'm aware of is the one on the official website: https://kbin.pub (hover over the Instances menu).
I haven't checked the fediverse server tracker websites if they added #Kbin yet.
There is a solo Kbin instance I came across: https://kilioa.org (I found no way to register, so I assumed it's solo).
For now, the best one to try, IMO, is fedia.io since federation works fine.
The flagship server, kbin.social is currently being hammered with a lot of registrations, and as such is temporarily behind Cloudflare's security settings… which is unfortunately affecting fediverse/federation requests.
@roomey Quick update.
I just saw this: https://mastodon.online/@mastodonmigration/110537944659327956
A new #Kbin instance is available here: https://u.fail by the admin of mstdn.social (@stux).