I would argue that follow/fav will turn HN into a other kinds of social media?

You want to hear/read interesting topics, comments and voice your opinion. While reading the favorite person's comment is really good, I don't limiy myself to that.

I normally go to NEW tab rather than just home page and to ASK tab occasionnaly.

Follow/Fav might just ruin my homefeed making me bias.

You can... the old fashioned way. Just bookmark a user's page and remind yourself to check it from time to time.

I realize this probably isn't what Joewee was asking for but maybe RSS feeds are a compromise? Lower amount of work on the programming side while still being able to accomplish this feature.

I post to Twitter for any of my hn posts using zapier and this:

https://edavis.github.io/hnrss/#user-feeds