Another possible useful feature would be to add "open in system" or similar in the right-click menu for a file, to open the file with whatever application the OS has bound to it.

EDIT: I see there's a plugin thing that when clicked installs the highlighting. Cool!

EDIT: Also missing is selectively staging lines of a changed file to commit. I would actually change the behaviour of the Git UI so that it matches the VSCode one, to reduce the learning curve. Most people already know how that works, no need to make them learn a new UX.