the fact alone that MGP has more access to MHPEs R&D will give them a distinctive advantage in terms of how to use the engine and exploit it to the max..
And who said a "A" customer gets all thats possible with the engine he receives? Isn´t it plausble that MHPE would work to a higher safety margin with engines for third parties where they have less control and possibility to monitor and handle on what is happening ? So Mcl or FI could well decide to make available more aggressive maps for longer time -putting engines at risk ....? so why not block access to certain areas of maps to ensure engines are meeting life expectance 100%? In your own team you can easily override this when men in power are prepared to take responsibility..