The O2 sensor is also only used during idle and low throttle situations. Rest of the time the sensor readings are not used. They wouldn't be any good anyways since the Rocket's sensor is a cheap narrow band one which is only good for a small band of readings around the 14.5 mark.
The ECU isn't as smart as people might think. Yes, it adjusts for altitude, temperature and load but changing exhaust and intake will mess up it's calculations, as well as yanking out secondaries. The resistor mod is a little safer than yanking out the secondaries but mucking up a complex system by shorting out one part of it isn't my idea of a good performance mod.