230bhp is pretty much the limit of the K03s turbo, so you wont get that from just a remap and breathing mods. Perhaps an extremely optimistic rolling road will tell you you have that much power, but the real world is somewhat different.
Reason being, the K03s can't flow that much air safely. 230bhp is at the limit and if you push it harder, you risk causing damage to the turbo. Tuners know this, so a good tuner wont push the turbo to it's limit with a stage one map.
There is loads of info on this forum about the limits of the K03s, but this post from this forum is a good read:
http://www.seatcupra.net/forums/showthread.php?t=242&highlight=k03s+flow
Plenty of other info in the Ibiza forums too, if you want a read.
With due respect mate, I've been in "Leon Land" for 3 years now. There is more to tuning than boost and turbo flow rates. Intake temps, ignition timing, injector duration, valve timing, EGT etc all play their part.
You seem to be limiting the scope of your view to the flow capabilities of the K03S. There is a much bigger picture. A lot of the engines referred to in your linked thread have smaller ports/injectors than the AUQ and don't have its VVT system. The AUQ is the ultimate incarnation of the 150/156/180bhp 1.8T engine. I'd be disappointed if I had Biglad's mods and didn't get 230bhp and 250 lbs/ft from a well written custom remap. The K03S will safely develop 1.2 BAR all day long.