The game keeps checking the 1-bit level switch while it's calculating its next move. On CP3000 PCB photos, the level slider is still connected to that single MCU pin. They must have added an oscillating circuit on the level slider.

So, level 8 on CP3000 will be as strong as level 2 on Mini Chess(disregarding possibility that CP3000 CPU is higher clock freq)
and on let's say level 4, the actual level is "2" 50% of the time, and "1" 50% of the time.

Some unrelated corrections to emulation I might as well mention here:
Mephisto Almeria until Vancouver, and Berlin too, are 12.288MHz, not 12.0MHz.
Novag Super Expert C that was thought to be version 1.2 is actually 3.0.