This is not really super important because we are very unlikely to assign a key
such as esc or up/down to a menu item. However, users might do this in a custom
commands menu, and in that case it is important that the builtin keys still
work; or they might remap those builtin commands to other keys, in which case
they might conflict with single-letter keys in normal menus.
Stefan Haller
7e3b24d496