Your fairly accurate, me thinks..
After spending a few hours of 'quality time' with the light, I too have myself convinced that the stator plate is installed well advanced statically, and the CDI produces more retard at low speed than high.
Naturally,the CDI has no idea when the flywhel is expected to come around again, it only knows when it did. More retard at low speed, then reduces the retard at high RPMs, gives the illusion (and effect) the CDI is advancing the spark as RPMs increase.
Sounds like we're both saying the same thing. I concur, a little more advance (er, less retard!) at low revs could be exciting. I loved the way my bike would rip off idle with the plate advanced, but when I saw the way the highs were affected adversly, I knew I was on thin ice.
Please let us know how your anti-foof cdi works out.