Tony
I believe you. I have read enough posts to know that you know what you are talking about.
I have looked, and I can not seem to find any information on why wrc cars etc vent to atmosphere. Some enlightenment here would be nice.
I suspect Porsche vents to the intake for many reasons. Noise, emissions regulations are two that I can think of.
FYI, I plan to recirc my BOV to minimize noise. I happen to be fond of quiet when I can get it.
As far as exhaust pressure goes it seems that will depend on many things. My intuition is to think that it would be higher than the intake since everything that is coming out came in etc and we can not forget that the fuel that was previously a liquid is now more gas. Now, given the right size exhaust the difference may not be worth worrying about.
Chris