He said it took a bit to wrap his brain around (Porsche shop owner 45 years) but he recommends the 0/40 and not the also listed 5/40...due to the internal oil gallery layout and size....designed a bit restrictive for that weight of oil so any heavier blend will raise oil pressures....is this your issue I've no idea...
I don't agree with that reasoning. Both oils are 40-weight at operating temperature, so the only time they behave differently is when the engine oil isn't up to temp yet. That W difference between them is small (250 cP), and most oils rapidly shear out of the 0W and become 5W (or even 10W) during their service life anyway.
I'd instead remind that different brands of 40-weight oil have different viscosities at operating temperature (the range is 12.5 to 16.3 cSt), and even the same oil at the start of its service life will have a different viscosity than at the end of that service interval. That may be what is responsible for the different oil pressures folks are seeing. (No one's said what oil they're actually using, though, so I can't say for certain whether this is the root cause of the differences we're discussing, or not.)
As for the boost pressure, the ECU limits the amount of boost needed to produce a certain power output. If you're at lower altitudes the turbo won't need to produce as much boost to create the desired power; at higher altitudes it'll need to create more boost to reach that same power output. So, I wouldn't worry too much about not seeing the maximum boost pressure.