Small vid about PCV

Not like that. It’s like AJ said. With a breather open to manifold vacuum when it drops at WOT any blow by will go right into the engine. The OE’s didn’t do that.

They have a breather that’s open to atmosphere so at WOT the blow by can go somewhere other than the engine.

IMO, the guy who made the video should have just blocked off the open breather all together and just let the PCV pull a vacuum in the crank case.
Ford never used a valve cover breather that was open to the atmosphere, so their system is exactly like @TrailBeast outlined and worked fine.