I wonder why there has to be a set menu option for kbin, though. It seems like excluding it in the default would be a pointlessly detrimental decision. No one would really look for it there.
There also needs to be some sort of filter setting for the search, I think. Another website's attempt at this utterly bombed by only searching the community titles, e.g. the first result on a search for "art" returned a star trek sub. This one functions a LOT better by utilizing sub description, but if I wanna find ask subs, for example, communities about dice making and otters come up before "AskScience."
Looks like you can only search for one at a time, and as far as I can tell it’s only indexing kbin.social, not any other kbin instances. Still, it’s a start.