I don't know about the newer generation motors, but on every other motor I have worked on, the PCV is to draw air/vapors/gases out of the crankcase by means of vacuum generated in the intake manifold, not put air into the crank case. This is typically done by means of a PCV valve/port on the valve cover connected to the intake manifold. That being said, I am not seeing how having a PCV on the VLOM does anything anyways, but again, I am not familiar with the 2017 generation of units.
My understanding is that on the Gen V LT motors there is fresh metered air from the air box connected to the valve/rocker covers. This is atmospheric pressure at idle. The heads have a passageway into the crank case where oil returns down to the pan, thus it's connected to the crank case. The PCV is located on the valley cover, which houses a check valve, to ensure the flow of air is always outwards (from crank case out). This PCV is connected to the intake manifold, which is under vacuum at idle. This means the flow of air at idle ultimately draws fresh metered air from the airbox, through both rocker covers, into the crank case, and past the PCV check valve and into the intake manifold. The reason why this does not affect the idle is because that air was already metered from the MAF, it's accounted for.
At WOT the airbox and intake manifold are roughly the same pressure (atmospheric) and blow by gasses are free to flow out of all three ports, which is how oil sometimes gets into the stock air box, but when you return to idle the oily residue in the air box and lines then gets drawn back down into the rocker covers and back into the pan because the PCV in the valley cover is drawing air using manifold vacuum. Please feel free to correct me if I am missing something.
So I am beginning to lean more towards reversing the flow of the drivers side rocker cover and use that as a PVC, though I will probably need to restrict that hose down to the size of the stock PCV line.
