While destroying a throw-away account used by a spammer on Ask Different, I noticed that the keyboard shortcuts are almost working:
M -> M -> 4 brings you to the following menu. According to the hints, I should now be able to press A to select the first radio button, but instead it focuses on the text area meant for additional information.
I couldn't find other input dialogs with a text area on the same level as radio buttons, but that's probably something the keyboard shortcut generator cannot deal with.