I've been working towards building out functionality close to what you're describing. As a first feature, I added annotations where the script looks for HN comm

I've been working towards building out functionality close to what you're describing. As a first feature, I added annotations where the script looks for HN comments quoting parts of the article and adds a highlighter effect. It lets you instantly see what parts of the text people are actually interested in. It's still a rough beta, but I'm actively working toward that exact vision.