Note, for certain communities opt-in is a better default than opt-out when it comes to category tracking.
Setting the mute all categories by default site setting, switches the forum to a mode where people need to opt-in vs opt-out
You would set it so people have certain categories default tracked, and then users can opt in to what they are interested in and have a very focused latest feed.
FYI @mcwumbly I think you were kind of interested in this problem in the past.