".....doesn't it follow that under boost this inequality is more unequal???"
Yep.Which really makes it scary, considering how many people like to run higher boost levels.Lean burn with the original intake seems inevitable.
Look...the guys at Porsche are engineers......not miracle workers

You've got that huge monstrosity of a fuel distribution/metering device and all that plumbing not to mention the monster air box...oh and I forgot...that bullet proof pop off valve....its cramped in there. A compromise had to be made somewhere!
"Any further ideas???"
The guy from rennspeed does rework the original intake for equalized flow other than that, run a rich mixture