Not sure if this is well known, but press period `.` when viewing a PR, repo, or file and github will send you to a in-browser visual code editor. Able to make commits in there too, perfect for [nit] comments
if you press it from a PR you'll get the vscode PR viewer which is way nicer than Github's (IMO, especially for larger PRs) the only thing missing is the ability to switch between changes from last commit, last review, etc.
I didn't know about it! I primary use a corporate hosted instance GitHub (so we often opt in to new features late), and I don't follow a lot of tech news on social media.