It has a "Flash Count" reset on the unit. Every time you reset it to the stock tune the flash counter returns to zero on the
ECU.
So ford should never know, unless they flash the car themselves and keep a flash count record on file. Which I highly doubt.
And if anything does break, ford has to prove the edit caused the failure. AND then if they do, Bluefin give you a warranty to cover the costs. (Though not sure on the fine print)
As for the power, the torque increase is great.
1st gear feels only slightly better (I think 1st gear still retains a torque limiter), from second gear is really pulls like a train. A much better improvement from stock.
Also overtaking on the highway in 6th is also greatly improved, pulls effortlessly.