Catch cans installed to catch miniscule amounts of blow-by
oil because that
oil reportedly drops octane rating in half is a crock o bs. I've never seen a catch can on a street car ever have more than a teaspoon in it after thousands of miles. Most catch cans are installed on supercharged systems. My Kenne Bell on my Shelby GT came with one and it never collected other than a trace after about 10000 miles. Didn't solve a problem but didn't expose one either.
Now, if you have more than that, and I agree, then the catch can is providing a diagnosis of a problem. If you have a catch can and regularly collect lots of
oil YOU HAVE A BIGGER PROBLEM. The catch can isn't fixing it. It's exposing it.
So if the OP wants confirmation that the PCV path is the cause of the lost oil then a catch can can help confirm that diagnosis. Perhaps a little sooner than removing the PCV system temporarily. The can confirms the diagnosis, removing the PCV infers it. But it costs more... In the absence of this kind of issue a catch can is only solving one problem: Adding more money to the seller's bottom line.
You can build a functional one for about $10 of parts from Home Depot.
Note my car with a SBF 427 didn't have a complete PCV path. Just some kind of K&N filter over the hole. It did show some oiling, but never enough to be a concern.