The solution: #1 repositions the torso. #2 keeps headrests in place. #3 doesn't create new pain points.
Quick overview: #1 You are not alone. #2 Beware of headrest modifications. #3 Know your seat cushions.
Engineering a cushion: something has to be repositioned: either the headrest, or the body. Both options are explored.
When it comes to seat comfort, short people are disproportionately disadvantaged due to headrest design angles.
Video summarizing the problem and the solution to uncomfortable headrests. Reviews design specs and population data.