To pile on the topic......width is important, but only relative to everything else going on.
The goal is to be able to balance, edge, pressure and steer your board to optium ability. Part of this is stance width, but also involves stance angles, cant/lift/learn, and also boot type/cant/lean. That's just the start.
Certainly not going to question your set-up with such improved results and Karl's assessment, but get to understand the impact of all the other adjustments....
K