Ok, I didn't try that one up to now. For me it sounds like "shut down player and turn on Navigation". What will happen once i arrive the target location = Zone to Navigate to? Hmm, will give it a try and report result in next few days.
For those people not using Oregon device it should not cause too much trouble as they (up to my knowledge) can use map navigation along with the running player. For those i would provide the map and they simply need to "install" it before playing the cartridge. May be that it is not that easy...?