Wow interesting read for sure.
I think something that will clear it up is to remember its not about vacuum its about high and low pressure. Air will always try to go from a high pressure to a lower pressure. Remember this is how the piston is pushed down the cylinder. So at any given moment if the air pressure is higher in the crankcase than in the exhaust then it will flow towards the exhaust. Upside of lowering the crankcase pressure is the pressure differential between the crankcase and the piston just got larger. free power not much but still free
I also read about dipsticks flying out etc mmm sorry the area being worked on in a dipstick tube is tiny and so its hard for it to make the load required to actually blow it out, if you have x amount of psi in the crank cases and then the dipstick equals 1/10th of a square inch then the pressure on the dipstick is x amount of pounds divided by 10.
Here is what I will be trying in my setup. 30/26
A catch can, breather bottle taken from the top of the rocker covers. One from the sump taken from well above the oil level.
I then plan on using a one way vacuum fitting into the exhaust to help pull a low pressure into the breather bottle.
The rocker covers will get an uprated baffling as well as a 1.5 mm restrictor in the front of the block and a total block on the back. normal cleaning up of oil galleries etc
Im always interested on feedback in case I have over looked something