This. Or just some way to keep track of a conversation without constantly refreshing

This is doable with hnrss if RSS is good enough:

https://hnrss.org/replies?id=devwastaken (replies to any of your comments)

https://hnrss.org/replies?id=19599229 (replies to a particular comment ID)

This exists, though it's a free third-party service.

http://www.hnreplies.com