Most people I ask are not even aware of the feature, or if aware, not aware when or why it is to be used.
And in order to check if it is working, the best way is to park close to a wall, say 6 mts (1.5 car lengths) away, put the headlamps on in the low beam position, and check if the beam pattern shifts with each switch position.
You need to give some time for the shift to happen, as these are normally motor driven, and will not be instantaneous.