The limiting factor of your current spec is the fuel injectors, they simply do not flow enough to push the turbocharger to its limit.

So a car with exactly the same spec engine, but with larger injectors fitted allowing it to run flat out, is never going to produce less power.

The next logical step for you is to jump up to a set of 55s, which will not make any more lag, as the turbcharger will remain the same, but it will be safe to run flat out at 32-34 psi peak tailing as rpm increase.

You would need an 044 fuel pump, chip to suit and a set of 55s. aswell as a large intercooler to keep acts safe and under control.