Interesting. 
:brainstorming mode now 🕵️:

Taking the post metrics this could be an interesting way curate a short form feed. 
Take their posting rate as the mean for an exponential distribution. Exponential distribution model "time until an even happens"

If you find someone is posting too much or too little, you raise or lower their mean posting, which results in the client sending out notes with some degree of sparsity according to the parameter.

how might that look like? UX - you just tweak as needed when you notice it.

Those that have been noted to post too little will have their notes collected since last login and disperse into the feed with higher probability.

those that post too much will take the notes since you've last logged in and shoot them into your feed with reduced frequency. You can even rank the posts.

Of course you get farther from the standard "timeline", but you'll resurface content you care about.