Now now
, Mr pat is a nice chap and knows alot about what he's doing with his car...which I am still yet to get a peek at. I see what you're saying though as there has to be a limit but nobody knows where and you can't be knocked for erring the side of caution
The way I see it is that all cars are different, perhaps sold as the same with the same spec but each have their own tolerences. Take ECU mapping for example, two 225 LCR's will not get the same figures when remapped next to each other. To put it into terms of this thread, the rods in one engine may let go at 250bhp and in another, 350bhp.
As I understand, the difference between AUQ & AMK/BAM internals were the pistons, which I believe were forged and the rods were 1mm larger in the AMK/BAM engines. However, all that means is that when going big turbo (nearer 350bhp+) is that the AMK/BAM pistons will most likely take the strain where as the AUQ ones will not but in both engines, the rods will perish meaning that for either Leon tuner, new forged rods are a must around this mark.
So to sum it up...
AUQ 340bhp+: New pistons & rods
AMK/BAM 340bhp+: New rods