RWD Cossie Wil, at the end of the day mate, none of the "pros" out there were born with the ability to map engines. So if Phil accepts the risk he may lose a few engines along the way learning, then its a skill I am fairly sure he can pickup and become good at.
"Pro Tuners" arnt godlike creatures with the ability to do everything from birth, they are normal people, like me and you, who slowly learned what they were doing....and refined this and are now so confident in their abilities they will map other peoples cars for money.