I can't help but feel while reading this thread that Burton is not so out to lunch with the EST/ICS system. It's nice to have a virtually infinite mounting range!
That said, I think I'd sacrifice ideal stance width to attain ideal centred overhangs.
Hard to tell from the pics, but here's how I setup my board(s): Put the board (with a towel under it if you want) up on your kitchen counter, and then tilt the board up on either edge, while pressing the edge into the counter. Tilt up until the boot/binding makes contact with the counter, and check the angle. My Nokia has an angle meter so that helps, but you can eyeball it or use a piece of paper and fold it to match the angle.
Then do the same thing on the other edge. If they're not almost identical, adjust until you get it as close to identical as possible.