Their one thing I don't understand with the belief that you only need a better intercooler for bigger turbo than K03 (starting at the K04).
Bigger turbo will heat less the air at same boost pressure than smaller turbo, isn't it. Also on a stage 2 with the KO3 blowing almost 80% more pressure you are at the edge of what the KO3 can deliver so it should have very hot air coming out. OEM iC was not thought for that kind of heat.
Plus as you are at the edge of what that turbo can deliver and then each PSI rubbed by the intercooler is good to get back.
So I would almost say that you need more a better intercooler than OEM that have minimale pressure loss a great cooling with a K03. But you will need a tuned to get the advantage of it.
for those who worry of lag try to think how many liter of air an engine of 2liter at 1bar of pressure at 3000rpm/mn is moving and how litle compare to that is a 10 liter increase of volume capacity in the intercooler.
I'm much more worry of pressure drop in the intercooler and at each bend of the pressure hose. for sure you will not see it because the ECU with N75 and wastage will compensate as much as they can but in a result of hotter air.