@Sketchmedic I'll take the liberty of replying here, I'm new here as well. I have 2.0TFSI and the few times I had the PCV hoses off and the amount of shi*e that's in them makes me want to install catch can and then decoke the engine, clean pipes and intercooler etc..
From what I gather so far, from reading this topic and countless others and "SHIRO-PCV-system-explained" on another forum, which helped me understand the PCV system due to illustrations (despite being technically minded I couldn't wrap my head around why does it need to pass under/inside the rocker cover, turns out it's jsut the VAG way), before I learned to understand the font > rear PCV and that the rear is basically just passage from the front I wanted to do 2 catch can setup because I was under the impression this is a separate circuit.
Yes you can add catch can inline with an existing system, and that is either before the integrated oil separator (the bump behind relief valve) and keeping the stock relief valve (no adaptation plate needed) or in place of the stock relief valve (you'd need the plate with 3 holes).
As others pointed out however it may be a good idea to verify that the PCV path doesn't have a leak inside the rocker cover.
I registered so I could ask
@I'm Just Rob. whether he still runs the same system or something else now, and if the same how does it perform 3 years in?
Also it may be just me but pipe OD isn't indicative of its ID hence I'm a bit confused did you tap larger threads on the can itself or just have large hose barbs to small ones?
The Czech guy,
@BrickRS Ahoj! So after you removed the filter and moved your hoses around does it still freeze?
Looking at your pics it's
crankcase -> catch can, front PCV -> catch can; catch can -> turbo inlet
Where does the pipe from rear PCV outlet go, or is it just blanked?