I actually think this is a very bad idea. the factory setup allows for PCV during boost. this does not. the factory setup is "good" and this one is "unacceptable". In other words, there is absolutely no reason to remove a perfectly good WOT PCV and replace it with... this. That is simply unacceptable. It just makes everything worse. This setup provides not one single positive benefit. The oil will become filthy faster, and power output will be reduced (possibly by 1-2%).
also,
Maintains stock prevention of crank case pressurization - Yes
I disagree. By opening a port from the crankcase to the atmosphere you invite atmospheric pressure into the crank case.
however, in a running engine, due to constant blow-by all engines produce, there will be slightly more pressure in the crank case than outside it during WOT. Which means the pressure inside the crankcase will be higher than atmospheric, even if just slightly. Which by definition, means that it is pressurized. As engine vacuum drops, and volumetric efficiency climbs, it will become increasingly pressurized. At idle there is enough engine vacuum to prevent an overall pressurization on a healthy engine, but that is NOT what that valvecover port is for: its for WOT.