Hmm, I hadn’t thought of that before. That would indeed be a handy feature to have.
The best approach would probably be to create a whole new admin menu section rather than displaying the original item as it would require keeping the "Appearance" section and having only a single link below it, which would be odd.
I may need this functionality for a new project I’m working on, so may add it at some point in the next month or so. I’m overworked with paying projects at the moment though so it won’t be added any time soon unfortunately.