HN does not aim to be infinite scroll social media which addicts you and makes you keep checking and re-checking for more obsessively. It is purposefully barebones so that you're not tempted to read every single comment and waste time.
Yet I do this more on HN than any other site since I don't know if someone's responded to me.
Noprocrast was... helpful, I guess, but I found myself racing to make poor quality responses sometimes, or HN was constantly locked out whenever I wanted to take a short break, instead of being able to take the time to respond with a thoughtful answer.
If you are going to post a comment that does nothing more than respond to the previous person, you are doing a disservice by forcing thousands of people to read text that is likely irrelevant or unhelpful to them.
The fact that this site is designed to prevent this behavior is one of its stronger points IMHO
Response notifications will primarily be used by people to dominate the chat, and your use case doesn't negate that.