it has the core functionalities down. but there are some relatively minor annoyances/confusion points in the user experience which should be fixed.
for context, this is from the perspective of viewing a post from a lemmy instance on a kbin instance.
when users talk about problems/culture/anything specific to their instance, they don't tend to specify which instance they are talking about. which makes things confusing for users seeing the post on other instances.
For example, the lemmy.world instance is having technical difficulties, a user makes a post saying "are we having technical problems with the site?", a kbin user has no information based on the title or content preview which instance that post is talking about.
a comprehensive search for communities in lemmy+kbin+other activitypub platforms does not exist. which makes it hard for users to search across the entire fediverse to find that one niche community that they enjoy. ~~searching for communities on a lemmy instance only shows communities from lemmy instances, and the same for kbin~~ For example, for a lemmy community to show up on Kbin.social, someone from kbin.social would have first needed to subscribe to that lemmy community by manually finding and entering its entire address name, only then would that community show up in a kbin.social search, or vice versa. if a kbin user has a niche interest, and a small community for that interest exists on a lemmy instance, they would not be able to find it (or at least not easily ie. needing to search through a second website that can access lemmy communities)
this may just be a personal annoyance, and it is also something more cultural than technical, but many users use either "lemmy" or "kbin" or the domain name of their instance to refer to the whole fediverse. which is probably just something that will always happen with new users, at least until the community and software becomes more developed.
The search function on kbin.social shows lemmy communities when someone on kbin.social first subscribes to that lemmy community. It will not show up if no one has subscribed to that community before you.
This is why niche communities will be hard to find, popular communities will be easy to search.
Even within kbin instances communities are not searched globally. For example, I made a Korean language community on kbin.social, if I search for it on another kbin instance like fedia.io, it will not show up. It's the same when you search on any lemmy instance