Adjustable PCV valve

If your engine is making that much blow-by as to concern you about sucking oil into the intake, wouldn't it concern you more about the blow-by in the first place?
Remember, at WOT, the PCV goes to minimum flow, the breather vents the CC gasses to the atmosphere, and the whole thing wants to run backwards. This doesn't happen only at WOT either, but at anytime the pressure in the CC exceeds the flow capability of the PCV.
Lets say you are just speeding up normally at PT and a vacuum of 8 inches, and say over 2400rpm . In this condition; If the engine is making more blow-by pressure than what the PCV is designed to deal with, then the excess will depart the CC thru the breather.
So yeah, at high manifold vacuum the PCV is running wide open, trying to create a vacuum in the CC. But as soon as the vacuum drops, the spring-loaded pintle inside the PCV, due to loss of vacuum, also drops; back to it's calibrated minimum flow. This protects your engine from excessive ingestion of oil-laden blow-by gasses.