Stephens: Terry can correct me if I'm wrong...

I suspect this is why they "cancel" the delay below 180 RPM:

The CH ignition does not use a fixed delay as I guessed in my first example. Using simple numbers again, the delay between sensor and firing at 1200 RPM would be 4 milliseconds (nice idle RPM), at 600 RPM - 8 milliseconds (a fairly healthy starting flip), at 300 - 16 milliseconds (a 'less healthy' flip), and so on. You have draw the line somewhere, and they chose 180 RPM. Below that, the system figures that you're not trying to start the engine, so it cancels the delay completely so that you can set the timing. If I understood Terry correctly in one of his other posts, the system only uses dwell timing for starting (up to 800(??)RPM), and then reverts to measuring between hall pulses (much more accurate).

VERY ingenious way to design an ignition system!!!