Ability to @mention followers or notify followers in replies (with rate limits)

Context

So before there was the follow plugin (and still ongoing!), the users on our forum have been using the existing core features in similar ways to a “follow” feature.

  • using a personal tag on topics, to let others set it to Watching first post — and thus receive a notification when the person posts a topic
  • letting users request a group to be created by a moderator, which they can then @mention for significant posts like posting a new project.
    • Rarely gets abused, though this is still all at personal discretion and under the eye of moderator discretion. People have the ability to join and leave groups. No users are owners of groups, since we do not allow PMs between users on our site.
    • In practice it works pretty well on our forum in the past ~5 years — dozens of people sign up to join others’ groups, and people @mention the groups. An admin clears up old unused groups.

The first dot point is covered by the Follow plugin.

The second dot point is a nice in-between, for getting notified about all topics vs. all replies.

Feature Request

Allowing users to @mention their followers (or notify them in some other way) for certain posts means that followers can also get notifications for replies, but only significant ones. Because getting notified for / seeing a stream of all replies can be a bit noisy & out of context.

It would be helpful with an in-built rate limit (e.g. max of X mentions/notifications in a day or week, that they can send out to followers).

Maybe it doesn’t have to be through @mentions but could be some post setting (“send notification to followers - 3 remaining for today”). Or something else altogether too, for the UX side.

If we could use the Follow plugin with this feature, it would remove the need for personal tags and groups that we have set up manually to replicate this. (Even though we unfortunately wouldn’t be able to install it unless it was on the Business plan, I think the functionality would be a nice option for others who use the plugin nonetheless.)