So today I learned something pretty interesting: AirPods that have been assigned iOS 11 exclusive left/right assignments such as "Next Track" and "Previous Track" still keep their assignments when used with an iOS 10 device. I learned this because I have a 10.5" iPad Pro on iOS 11 while my iPhone 6S remains on 10.3.2. Today, I set my right AirPod to skip to the next track and the left one to go to the previous track while listening to music on my iPad. Upon listening to music later in the day on my iPhone, I was pleasantly surprised to find that I was still able to skip to the next or previous track by double tapping the respective AirPod. Basically, its seems that the AirPods hold whatever double tap function they were last assigned.