Ha ha, love this.
It just so happens that I am working on a tool that ends up expanding hacker news urls. The problem I was solving was that of managing lots of replies to a successful post.
I allow you to replace the "ycombinator" in a hacker news item url with "gipety" so this current thread would point to:
https://news.gipety.com/item?id=41780255
You will then get a page that remembers the comments currently displayed. On subsequent refreshes you will see any new comments highlighted in green.
As I worked on it I decided to also add a slug as I got tired of not recognising what the urls I was copy pasting were referring to.
The above will for example end up generating this:
https://news.gipety.com/hn/41780255/k/67/s/show-hn-i-made-a-...