What I would love to see would just be a map that concentrates on whats important for navigation: Railroads, Streets, Rivers/Lakes and most importantly woods.
Having this illustrated in a visible contrast rich way would allow for very good navigation.
I can only mention IL2 again. The map there is VERY good for navigation. No icons or markers needed.
You can open it easy and on the fly and manage it while in flight.
DCS should take a peek at that.
Not talking Flightmodels or anything else. (except for maybe airplane variety when it comes to WWII;)).