I doubt the forum will get a feature which you can get from an external site: several sites offer to monitor a certain webpage, and send you an email if it changes. If you use that on the link I posted above, you should get notified when I open a new topic.
For example, I choose 10 users. When I visit recent posts page, only posts made by these 10 users are shown.
I was thinking of offering this as a service to signature campaigns (either companies or managers). As a demonstration, it currently uses data from just over a week on all ChipMixer signature participants (it doesn't get automated updates yet). A real version would get automated updates (depening on the page it will vary from several times per hour to several times per day).
All I'd need is a list of userIDs in a campaign (and regular updates), and I scrape (almost) all posts within seconds of being posted (I don't check the posts for being edited after that).
This can give a quick overview of the currently active users and topics, and it instantly highlights the most active users.
If desired, I could also exclude certain boards or topics that are excluded from a campaign.