Don’t know about whether the Dreamscience maps leave a trace, but there’s a confirm case on the RS owners forum of someone having a warranty claim for a blown engine refused because a trace of a Mountune map was found. Be careful out there!
I think what DS are saying is that Ford can’t tell what the map was, but they can certainly tell it’s been flashed. I don’t know the techy side too well, but a Ford service manager told me there’s a data logger component in or attached to the ECU that records such things. This is why some are saying don’t remove a map if you need engine warranty work done – best to be honest.
You can flash your ecu as much as you want it your bloody ecu not fords. And no way on earth Ford can refuse your warranty claim if the count of flash’s as you well know the first thing Ford do is plug a laptop in your car.
Don’t comment on stuff you don’t personally have our used And tested your self.