I always believed that the car reduced/limited boost via the EBV etc in first two gears and that the Gtec chip together with the disconnection of the EBV removed this 'restriction'?
It's a limit on the rate at which the boost can rise IIRC. If you upped the power but didn't remove this function, it would start to work in higher gears too. The ECU has no idea what gear you're in.