OK I'll chime in....the timing advance is created when the RELUCTOR is made to rotate away from it's original relationship to the pickup. THAT is what initiates timing advance because now the trigger relationship has changed!
All the rotor does is transfer that change to the cap. The rotor moves but that is why you have a broad tip on the rotor, to transfer that advance from the reluctor/pickup without deteriorating the cap and rotor due to excessive gap.
