I wonder... at one point I wrote an extension (for the moderators) which had the ability to essentially follow users. Think of it as a news feed for HN.

Really wish I could make that open source if no one is using it lol I use it personally to follow people on HN which post interesting comments (still works after 4 years with no edits)

Is that a question for us? I'm not aware of what you're referring to.

It was, But the lack of knowledge of said system is probably indication it’s not being used :)

Have you considered integrating the extension's features into the main site? (Is that were folding came from?)

We've considered it, but it's way more Javascript than we're comfortable introducing by default. (Actually it's Arc compiled to JS, another piece of software I'd like to publish someday.) Most likely, we'd make it an option you could turn on in your profile, so you'd get the functionality without having to install an extension.

(If by folding you mean collapsing comments, that was implemented separately, as part of HN proper.)

This is exciting to hear, hope to see it soon :)