The addon uBlock Origin has an option for rules to change HTML and could be used for this [1]. Replace Username with the persons Username. add to My Filters. I encourage people that dislike or often find themselves disagreeing with or being activated triggered by me to do this for my username.

[1]

    news.ycombinator.com##tr.athing.comtr:has(a.hnuser):has-text(/\bUsername\b/)

There's a userscript called 'HN Blacklist' that can hide/filter content from users, titles and sources: https://news.ycombinator.com/item?id=43282379