https://keycodes.vercel.app/ displays different pages for the right cmd key and the left cmd key, however, the URL stays the same: https://keycodes.vercel.app/for/meta.
The same happens for the option keys: https://keycodes.vercel.app/for/alt
The app could show different URLs (https://keycodes.vercel.app/for/alt-left and https://keycodes.vercel.app/for/alt-right) for the two keys since they correspond to different codes.
If this is something that you'd like to have @wesbos, I'd be happy to raise a PR over the weekend!