I would add an ability to follow more than 5000 people. I follow mostly AI/ML researchers in the field and this limit is nausiating. Why can't there be more than 5000 interesting people in the world?

I would also add ability to privately mark people as "Friend", "Collegue", "Trusted" etc so that I can influence algos to show more stuff from people I care. Facebook has this feature to mark friend as "Favorite" and it has seriously improved my newsfeed. Unfortunately, they limit it to 30 and it's just nonsensical.