Using two stock light springs in distributor advance, good idea?

Going off route on the thread here a little, and am somewhat skeptical, but I did read about a rather stout 480 plus inch 440 build that had a 21 hp increase with this system over an MSD 6 AL on the dyno. If true, I suspect that it would be more of the engineering of the timing curve constant to rpm in the electronics than an actual spark energy increase, but I would like to hear HalifaxHops' and Andy F's input on this. At my performance level, as long as it isn't points, I am happy!