MNBox wrote: "But, the DME does retard the Spark, that is, produces it Later in the Engine Cycle."
You are correct in your revised statement... The DME *retards* the spark timing when it detects knocking from the use of low octane fuel.
The low octane fuel burns quicker, igniting faster, which forces the retarded timing.
That just flies in your earlier statement, which bears correcting.
Happy motoring!
Jack
