While this isn't codified in the HIG somewhere, we wondered whether it
wouldn't be better for the "Core Layout Configuration" tab to use radio
buttons instead of the current "Ignore system configuration" check box.

With radio buttons it would look as follows:

  (o) Use default system configuration
  ( ) Use custom configuration
      Keyboard model: [ Whatever ]
      [ ... more settings here ... ]

(With the above radio button selection the settings-widgets would of course
be insensitive.)

The above arrangment seems a little easier to understand.