Are there any hard numbers about how much time can actually be saved that way? Letting the aircraft run down the runway after touchdown, then slamming the brakes in order to come to a screeching halt just in time for the desired taxiway is sure to cause much discomfort for the passengers and unnecessary loads on the brakes and other structure.
Simply putting the aircraft down in the touchdown zone and then applying a constant deceleration to make the same exit by contrast is much more convenient for the passengers and I am convinced that this second method "costs" less than 5 seconds of turnaround time. Even with a minimum time turnaround of 30 minutes on my type, this can well be accepted as much more can be gained or lost by efficient ground handling.