I’ve seen this mentioned a few times already: people wondering why certain communities don’t show up in their instance. You need to first search for that community via the magnifying glass icon and type in “!communityname@instance.domain”
Notice the exclamation mark at the beginning. Might take a few seconds. This will teach your instance about the remote community.
Interesting, I might look into modifying the extension for it to work with kbin
Sweet! I would be interested, and might be able to help test. Let me know if something comes of it.