Mobile: <fullscreen> vs StageDisplayState

Can someone explain to me what the difference is between <fullscreen>true</fullscreen> and StageDisplayState.FULL_SCREEN_INTERACTIVE, and how these should be used?

Testing on an Android Nexus 4 it seems to be that:

• StageDisplayState.FULL_SCREEN_INTERACTIVE hides the status bar at the top.
• <fullscreen>true</fullscreen>  hides the status bar at the top and initially reduces navigation buttons to dots, when they are touched they become full icons and stay that way.

Questions:

• Is this the only notable fullscreen behavior on Android?
• What is the behavior on iOS?
• Is there any way to return to the initial state of <fullscreen> (with the navigation buttons reduced to dots) from AS3?

Thanks!

-Aaron