As someone trying small instance I have to explore other instances using good old browser and then try to open it in Boost. For some reason sometimes it just doesn’t work, even for communities that are in lemmy.world! Ones I have tried and failed are:
https://lemmy.film/c/moviesandtv
https://lemmy.world/c/linux_gaming
https://programming.dev/c/programmer_humor
And some others I may have forgotten. For comparison, if you click https://lemmy.ml/c/asklemmy it should correctly open in Boost instead of browser.
Yeah looks like I still have to use the browser more than I thought I would be. At least I hope the search button up there on Boost works for that “once per instance” thing someday.