This is great, it'd be amazing if there was a place to comment on directly about the page using this extension or otherwise a central database where all discussion about a URL exists beyond the control of the page itself.
There are other extensions that provide just the commenting part (e.g. https://web.hypothes.is/, https://curius.app/, https://glasp.co/), but I find that they suffer from the cold start problem, i.e. it's rare to stumble upon comments for a page you go to.