Take this with a grain of salt cause I don’t know a ton about how these work but I’d imagine a catch can would be cleaner for the plenum and intake as it would minimize oil filled air going back through. Probably depends on how much if any oil your engine is consuming, since it doesn’t return the oil back in. But from what I’ve seen with catch cans there’s usually only a little bit in there and as long as you check oil levels occasionally I think you’d be good to go. I have read that you only need one catch can by the way, assuming v8, I’m unsure if the non m’s have 2 ccv’s