Sometimes when I submit a PR and I get a lot of feedback I get lost making sure I've addressed every comment. My #1 feature request would be being able to mark comment threads as resolved. The outdated comment feature sometimes works for this use case but mostly it doesn't.
I didn't see it mentioned but it looks like you can now 'react' to comments, a la facebook. So you could choose one reaction, say, "Horray!", and use it as a marker that you resolved it.
Now I wonder if the commenter is notified on every reaction. The only thing that might make this more difficult.
That would also be missing a filter to show all unresolved comments, which is a huge use case. (Or maybe you can do that, if you can it is not very quick and intuitive).
