Hacker News Reader

I figured since for Reddit this functionality is provided by RES, for HN it should be HNES so I searched "hacker news enhancement suite" and found this [1] which does list "Ability to tag users" among its features.

[1]: https://chrome.google.com/webstore/detail/hacker-news-enhanc...

You can use Hacker News RSS [0] and subscribe to a user's feed [1] via https://hnrss.org/user?id=USERNAME

[0]: https://hnrss.github.io/

[1]: https://hnrss.github.io/#user-feeds

Create a bookmark category for HN users you want to follow, and bookmark their comment pages.