You seem to ignore the fact that people ignore ux advices. You can ask them politely, but they'll still slap something together and call it a day. And there's no way a complex control that you described can get into popular ui libs. Or to be approved by all "designers". These default looks of type="radio" and type="checkbox" are the last stand. If you break it, you'll complain even more but nobody would listen still. Cause defaults and easy ways rule the world. Accessibility is a rough battle already even without ideas that definitely won't work.