I've started running some tests in my test group. I edited a wiki page. Here are the issues so far:
1. The hashtag does not come into existence until the event (e.g., edit wiki page) occurs. That does not allow pre-editing. In the example of wiki pages, and probably others, I don't want notification messages going to the group. But there's no way to prevent that a priori, because the hashtag does not exist a prior.
2. I didn't get a push notification.
3. I'm not sure about whether a general hashtag edit makes sense for these special tags. I like that there is (I now see, once the tag came into existence) a way to prevent the notification from being emailed to the group. But I feel like hashtags are not the right kind of thing for this. It feels like a square peg in a round hole. I don't see any obvious problems yet but I feel like they will surface eventually.
Messages are the sole opinion of the author, especially the fishy ones.