When using the shortcuts while reviewing a bunch of pull requests, it would be nice to get a confirmation popup that asks whether one is sure.
Eg: "Are you sure you want to approve / unnapprove this Pull Request?"

Reason being, is that I am usually at the bottom of some file I last reviewed whet hitting Approve, but due to the number of PR's I deal with daily, I sometimes hit the "A" shortcut on PR's that I have previously approved, which unnapproves it. Then I have to approve it again, which confuses the PR creator, as it seems like I unnapproved and reapproved it for a reason.