Re: customizing key definitions with Customize

[Richard M Stallman]

    what the user will see: all current key bindings in this keymap
    (this may be too many as some keymaps have dozens of key bindings),
    or an empty list with the single [Insert] button to add new key
    bindings that will override the existing ones after saving the
    Customization buffer.

Perhaps we should handle this with two alternatives, like
customization of fonts.  You can customize a font either in terms of
its appearance in the current kind of screen, or its general conditions
that apply to all kinds of screens.