In event filter, most of the usual Expression parameters are not available such as app properties, issue. You can receive list of changed custom fields but you don’t know what each one corresponds to (customfield_101101 ==> What is this field? We are only interested in fields configured in our app). How are we supposed to filter events here? If we can’t filter an unrelated event (most of them are), we are rate limited by update operations performed by another app. Because it generates lots of unrelated issue updates in the background.