I have several P3's (don't ask). Some have been 'grey imports' , one has been a UK sourced machine and one shipped by DJI directly to the UK. There is no difference in output when measured at the Tx output connector when the transmitter is on the bench with the aircraft powered on and off. So I am really puzzled at how the regulation of the Tx power occurs. Clearly there must be a difference in output between FCC /EEA as it would be inaccurate to claim differences and ship the same unit worldwide - how this happens in practice is a real mystery. Not sure if the aircraft has anything to do with it when in flight? I wonder if the Tx power increases as signal strength from aircraft drops off. I have also tested x2 Inspire Tx which were sourced from Hong Kong and they are pretty much the same. The theory that your Tablet device may dictate the Tx power may have some merit - proving it is a lot harder.