Ok, I think I understand this now. Please just confirm this:
If we have an OAT of 20ºC and we set an assumed temperature of 50ºC, the FADEC would calculate a throttle position which would be at a lower throttle position than if we set the OAT of 20ºC, in order to keep the Turbine Inlet Temperature within its limits. Now as we need to input both the assumed temperature and actual OAT, taking into account the density, the position of the throttle that the FADEC calculates would be, as a matter of fact, even lower than the assumed temperature as the density is the actual density at 20ºC and not at 50ºC.
Thanks a lot.