I didn't have the car in my hands so the model uses the default CG height of 31mm. To do a valid comparison you would need to have multiple cars with exactly the same components installed, setup the same way and a very accurate test method. You are looking to measure differences of tenths of a mm so test accuracy is critical.

You could try asking XRAY how much the CG lowered from the T3 to the T4. They definitely have the number from their CAD models.