This last bit doesn’t make any sense. There is a check valve in the OEM PCV that prevents air going from TIP to PCV. The purpose of the connection to the TIP is to both provide vacuum to the crankcase and vent crankcase pressure from blowby.
Speaking of which, OP, your method of adding a “catch bottle” was preventing the PCV from doing its job of venting crankcase pressure I would think... this could explain the smoke later on using that method.
If the PCV doesn’t vent, oil will get past your turbo seals, your upper timing cover, basically it will start coming out everywhere it shouldn’t and this will cause smoke. This happened with my VWR plate once it busted.
VW SSP 606, I was asking about pcv operating in post 6 of this thread and someone pointed me to that. It's translated from french so some of the wording is a little funny but you should be able to figure your way through it...you can find it by googling it. As far as the vent pointing the other direction, the document covers the whole EA888 gen 3 engine platform, so there are going to be slight variations here and there but it shows the basics of how it works just the same.
Not sure what to tell you other than standard internet research....it's best to consider the source and always "trust but verify". It sounds like maybe someone had just enough knowledge on a topic to be dangerous lol. Unfortunetely if incorrect things get repeated enough they can become 'facts'.
I've had mostly mazda and ford turbocharged engines in the past and their PCV system is quite different, but same principles/goals apply. Most systems have 2 separate vents on the crankcase somewhere, one connected to air intake pre turbo, and other to intake manifold and follow the same basic 2 way system design. VW/Audi just has this complex piece on top of the engine that does it all in one... it's pretty cool design I think, but obviously has issues with high boost and track driving.
I can't remember exactly the details of your issues but losing that much oil on track sounds more like an oil control issue... like the whole pcv plate vent area is getting flooded with oil from extended high rpm and/or cornering/braking, and then you're back on the gas and the blowby crankcase pressure has to force the fluid out with it.