Oil catch tank

[analog_me]

Hi all,

What is common wisdom for the usual oil return lines originally installed between the plenum and the cam cover on the K when fitting itbs?

I have seen people blanking one and using a small filter on the other, and some using catch tanks.
How does a catch tank works? is it needed?
Were does the return line from the tank goes?
Thanks

[V7SLR]

Wet or dry sump?

[analog_me]

Wet