I'm not convinced the relationship is casual. For example, couldn't the people who already had experience be enthusiasts who are more interested in driving generally?
The simpler explanation is that drivers familiar with the feature aren't task-saturated managing the feature.
It's like learning to drive for the first time: you're task saturated just keeping the car driving straight and at a consistent speed. After a while you learn to manage that and then your attention turns to other aspects of driving the car.
It's like learning to drive for the first time: you're task saturated just keeping the car driving straight and at a consistent speed. After a while you learn to manage that and then your attention turns to other aspects of driving the car.