[Xaxas]

So I'm still learning how engines work and I care about engine longevity, so PCV and valve gunk are a serious concern for me in a DI engine, I understand how the "dirty" side works, crankcase pressure that gets past the rings is vented alongside tidbits of unburnt gas and oil as the foul substance known as blowby, so something has to be done with it and is reintroduced into the manifold to be burnt for emissions/regulations and I guess it uses the vacuum from the air coming in to help vent pressure right? I already have a JVC catch can that has caught a fair bit of oil for 2000 miles.

What I don't understand is the "clean" side, I know it goes into the valve covers from the intake and before the TB, how does this work exactly? Is it moving intake air into the covers or pushing something from the covers back into the intake? I've also read that you can install a breather to prevent the recycling of whatever comes from the clean side, what would be the negatives of this? Do you just block off the intake tube if done?