I'd give Cain at Wolf Performance a call , with the GDI engines in the racing club sports we've had a number of diffciult to find issues the most common is the the throttle bodies.
He should be able to give you some help in identifying the problem.
Met Cain yesterday and he mentioned about sticking throttle bodies on GDI engines. I can confirm the OBD Torque Pro app working with ELM327 bluetooth dongle will display both pedal and throttle position and would therefore show any issue there.
Worth noting that my Roadster which runs fine, displays max 80% for pedal position with corresponding ECU limited max of 75% on throttle. Apparently this is not unusual as the extra makes little difference.
