You should be able to have maps in the Active Info Display no problem, regardless of which nav unit you have. There is a 'button' (it's actually a touch sensitive button that pops up on the bottom of the touchscreen when you move your hand near its proximity sensor) that allows you to switch between maps on the touchscreen and maps on the Active Info Display.
What you can't do with the standard Discover Nav, is have route guidance running in both the Active Info Display and the touchscreen at the same time. That feature is a Nav Pro feature only.