In some cases the PCV contributes to the problem but bulk of what ends up in the catch can is directly related to how poor a job your oil is actually doing and in the case of a DI engine, it's a cost the engine can not deal with. It's ridiculously easy to test, replace the 0W or 5W oil with something thats heavier (no not 5w30 instead of 5w20, move to 10w30) and you will instantly see a difference, a difference that will continue to cut down on the sludge the can catches. My Coyote is what we typically see, barely a trace in the can on heavier oil, yes even after a full day of lapping with it buzzing 7-7500 rpm all day. Same results in everything we've tested. Spin off of all this, your now using oil that will actually protect the engine long term.