I think I’m having same problem with my ka-t though - but mine started to burn it up during boost throwing oil right into throttle body through I/C piping - trailing blue fog behind me. Check if yours also does that right after boost.
I want to find a place that can test seals on my spare t25 - I think this one has blown seals (return line is fine now and running a much smaller restrictor - I think that’s what damaged my seals before).
my car is currently jackstand racing and oil feed for the turbo is fucked, so no running and no boosting for me.
i think i am going to try tapping the first line for the catch can into the intake pipe itself instead of the filter.
also i am stripping my bings manifold and GT28 off today infavour for stock and running the stock catch can again, i have to leave for quebec friday morning and the car hasn’t been drivin in almost 3 months
if your motor spews oil out of the breather on the valve cover and crank case it usually means that your rings are bad or cracked, and then the next step after that is the dipstick blows out.