It’s a long window (up to 2 hours), but it’s not a cheap lookup… it checks all the posts back to your backfill date, multiplied by the number of languages, multiplied by content type. Someone sitting on that page triggering it every minute wouldn’t be ideal.
Even with a button, we’d probably want to rate limit that too… what sort of information are you looking for? do you need some confirmation that the process is still ongoing? are you waiting for a specific result?