But as of different android-versions and phones it could be that there is a phone or tablet which has no hardware-back-button and you will NEVER see the items added with AddMenuItem3. Maybe your app runs in FullScreen (no titlebar) then there is no place for the standard three-point-button on devices without hardware back button. Or even you want to design your own titlebar with AHActionBar for ex.
In that case you have to build your own menu.