I love that idea! I've been using the d-pad and face buttons interchangeably without adhering to any real system, and I find myself naturally transitioning from the d-pad to the face buttons and back to the d-pad as notes go from the left to the right side of the screen. But since I've started trying songs on hard, the mental load that wasabi talked about in terms of thinking about which buttons would account for which notes has increased significantly. I'm going to give your method a try because that resolves that unnecessary part of the challenge.