Just to clarify why using channels 12, 13, and 14 in the US is a bad idea (aside from the whole legality issue): The area of the ISM band in that is used as channels 12-14 in other countries is reserved for low-powered telemetry and control of medical devices in the US. Causing interference on those channels could endanger a patient who is in an area being covered by the Yagi being 'swung around."
As far as "playing stupid", it would be rather hard to do that. If someone is smart enough to modify the equipment using European or Japanese firmware, they most certainly are intimately familiar with radios, their uses, and the governing regulations. Besides, there is a very old saying: "ignorance of the law is no excuse."



