Correct, carbon build-up on the backs of the valves is a widespread issues across all direct injection engines (DFI is more common than ever, in part to more stringent CAFE(MPG) standards, whether that be domestic, Asian import, European). Some manufacturers are now combating this with a DFI/PFI hybrid--sticking an add'l fuel injector above the valves to try to clean the backs of the valves a bit.
That was a well-done video, but while a catch can setup can help DFI engines in many ways, on the European side, I've also seen it cause many problems when catch can kits or DIY'ers get rid of some important factory crankcase breather components. First thing a DFI deserves in my professional automotive opinion are;
--oil changes with a high quality synthetic oil(oil which meets/exceeds factory manufacturer approvals) and factory filter, well before the manufacturer recommended mileage interval. Many manufacturers are now stretching recommended oil change intervals to as far as 20k!, and they're using lower quality "crap" oil to put more profits in their pocket. This combination heavily contributes to the breakdown of the oil, causing even more "filthy crap" to be "floating around" in the engine and crankcase breather system, which attaches to the backs of the valves, which over time build up enough to become large globs of carbon as he showed in the video. Enough of these carbon globbing and the valves may not seat fully, causing misfires and possibly flashing CEL. Change your oil at 5k (again, high quality full synthetic, factory filter) and you'll be better off with or without a catch can, than you'd ever be if you changed oil at 20k with low quality junk and yet had a superior catch can setup.
--when driving, once oil/coolant is up to temp, a bit of the old "Italian tune-up"; get the RPM's up and throttle down, helping blown some of this carbon build-up off of the valves. Yes, you'll see a large cloud of darker gray exhaust behind you, but that's how you know you're doing good work.
--remember to change your engine air filter at or before manufacturer recommendations (definitely before if you're driving on dusty terrain as we often do). A dirtier air filter will reduce engine performance, but can also lead to dirtier air being ingested into the engine, contributing to more "filthy crap" traveling through the engine.
NOTE; if the engine hasn't been maintained well and large carbon globs are present, we've had very good success on the European side with a professional walnut blasting procedure.
Before and after;
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And as always, YMMV.