I'm about to launch a Lemmy app (by Monday, my friend yelled at me when he found out I'd been using it exclusively for weeks without putting up a beta), and kbin support is on my to-do list.
Frankly, I started using Lemmy, saw this could be the thing I've been waiting for, and decided the edges were too rough. So I made the app I always wanted for Reddit with the goal of using multiple servers, multiple accounts seamlessly. My guiding philosophy is making the client into another layer of federation,
I checked out the kbin docs and I can probably knock it out in a couple days, I've got abstraction layers to handle different versions and forks of Lemmy... Head over to !flemmy@lemmy.world and let me know this is something people want and I'll put it higher on the priority list
Artemis developer said they're gonna public source the code soonand their app supports both Lemmy and Kbin, which might help you with Kbin support. Just a suggestion, I know nothing about how code works, though.
If you add support for kbin, you'll probably going to add support for kbin's microblogging feature. If you added support for kbin's microblogging, might as well add mastodon support. Heck, might as well add pixelfed support to the mix, why not? Voila, now you have a super federated app.