AFAIK, even though <menu>, <hgroup>, <header> and section are listed as supported tags in the Kindle Publishing Guidelines (KPG), you cannot use them to create interactive Kindle content. IMHO, the tech writer in charge of the KPG most likely simply copied and pasted most tag definitions from
Quackit without fully understanding them. They even included deprecated tags such as <hgroup>. They also included <output> in the official list, which is rather pointless without <input>, which is not on the list.
OTOH, several
CSS3 elements that aren't officially supported according to the KPG, actually work on all currently supported Kindles.
You can, for example, create quizzes with answers formatted as upside down text using 2D Transforms.