I don't like to answer the phone in the car, so have only used a few times... and no issues on my end, and nothing said from the other party (yet)... on android.
Yeah, not sure where the requirement comes from, but apparently as the headlights can only be seen one at a time when standing off to the side, someplace requires the other "headlight" to be visible at a certain angle or some such hooey.
For pedestrian notification... so they know they are getting hit by a car and not a motorcycle, as only one headlight is visible when looking from one side or the other.