The one point here that's relevant to me is that if you use a service worker and then redesign your web app so that it's no longer needed, now you need to host code that removes the service worker, and you can never remove that new code, because there may be users with the sw installed who don't revisit for years.
Service workers should have an auto expiration. Maybe a month or so.
Service workers should have an auto expiration. Maybe a month or so.