For the CDR I fabbed me up a catch can, as follows: I came off the timing cover with a short piece of aluminum pipe, tig welded a 2-1/2" pipe 4-1/2" long to it, filled the larger pipe with steel wool with a stainless perforated metal screen on each end to keep bits of steel wool from being drawn into the intake, and from the top of that, a clear hose into the intake, post filter. So far I really like how it's working. The clear hose lets me see how much oil is going into the intake, and so far hasn't been really enough to talk about. Oh yes, I spaced the perforated metal pieces up from the bottom and down from the top so it wouldn't restrict airflow.
Thought about a pushbutton for the GPs but decided against it for now. Nice to have it stock in case someone else jumps in the truck.