We’ll, now that’s interesting.
It was my understanding that Nissan switched to plastic VCs in an effort to reduce operational costs across the board but I can see how they would also absorb oil. My passenger side VC is saturated all over.
The baffle under the cover helps to secure the seals as well as provide some type of air flow regulation for the varying pressure when in operation. It’s my understanding that if the seals were to fail, the baffle would also ensure that they don’t fall somewhere they shouldn’t be.
If oil vapor absorption into the plastic VCs is an essential part of the operation, this implies the need to install the oil catch can.