Yeppers, I understand that Plums.
But it seems that Mikes catch can is plumbed so that both the inlet and outlet is receiving the came crankcase pressure.
I notice on the holden forums that many use a catch can to collect
oil vapor to prevent contamination of the inlet manifold but usually the feed is from the crankcase/tappet cover (same pressure) to a catch can, then to the inlet manifold.
The object being to collect most of the
oil vapor before it can contaminate the inlet.
Maybe there is some weird science going on that I don't know about. (highly likely)
Ahhh edit......the pressure is venting out the gauze/breather....got it. No recirculation...just venting and catching
).