The way I see it is your right. When running in closed loop the O2 sensors will feed back and the injector on time will be cut, but acceleration is usually (always?) open loop, particularly as the Crossfire has narrow band sensors and can't control AFR. Larger injectors will flow more fuel during acceleration - that doesn't mean anything will happen quicker though, we would need to see the car run with AFR logging to know if more fuel would help. Other issues might be overfueling at cold starts when the system is open loop until temperatures rise, perhaps damage to CAT converters etc.

If the duty cycle is over 80% at full power that is unusual and reducing the duty cycle would help control fuel supply.

Malcolm