have you ever mapped one vented to atmosphere then changed it to a vacume breather system and saw the difference?

im not claiming to know everything all im saying is that this is tried and tested on two cars i know, one being mine, nothing except the breathing system was modified and both went from filling catch tanks in a few laps to not even a little going into the tanks. (should mention both cars have reciently had forged pistons and rods etc so damage inside is highly unlikely)

yes i agree the dip stick coming out is the most extreem and will only occur when the breathers are blocked or as you say internal problems

the main issue with the non vvt is that the block breather doesnt route seperated oil from vapour back to the sump

dry sump is the ideal, or running an external vacume pump but using the intake or exhause to create a vacume is enough to notice a difference from breathing to the atmos. its the route the oil vapour takes to get out of the engine wilst seperating oil is the secrete to the system