Neat find. Thank you.
Obviously, it can only search one way, so subreddits that are combinations of words only find communities named exactly the same (e.g /r/andor finds [email protected] but /r/StarWarsAndor doesn't, and /r/starwars doesn't find [email protected]), but given how many communities are named the same, that's not much of an issue (and it can always be supplemented by manual searching, of course).