That is not the same thing as changing the crystal in the transmitter. What you are changing when you swap the module is you are actually changing out the ENTIRE transmission circuitry of the radio. That module has been properly tuned to be on frequency. The crystal is the part of the transmission circuitry that determines the frequency you are transmitting on. The crystal is what we have been referring to here in this thread. Your module is something different and doesn't apply to this.

Ken