and looking back at your pictures, have you actually fitted the catch can to the breather tube rather than the exit tube with the PCV valve in it?
Tell me altea-ego, where is this supposed PCV valve on the 2.0 BKD Engine? The documentation you have shown is for a Corvette V6/V8 not a VAG TDI engine.
I have searched through ETKA and cannot find any PVC Valve fitted or a breather pipe that comes from the crankcase and enters the Air intake/FMIC pipework. I have tried following the Air intake ducting on my BKD engine and cannot find any other PCV/Oil breather pipe entering the Air Intake pipe work.
Your explanation maybe worthy of a mention but seems totally irrelevant in this case.
If you have read several threads in this Altea Forum, there are a number of guys reporting Oily FMICs this is due to Oil from the Rocker cover being sucked into the Air intake via this pipe.
When I check my own intake from the breather pipe entry point and put my finger into the inlet of the Air intake pipework to feel there was considerable oil on the inside of this inlet. Thus the reason for fitting an OCC here.