how is a catch can going to protect the baffling?
And oil vapour, is a gas. It will not become a liquid just because you put a metal mesh inside a can. It may settle out as a deposit of carbon; the black "crap" that keeps getting referred to- as you have noted, settles out inside the valvecover, all over the insides of the engine, and anywhere it can. But keep in mind, this same oily vapour exits the valvecover via PCV valve and enters the intake manifold directly without any kind of filter or can. So adding a catch can will not solve the issue of oily vapour settling out, or inside, the engine. It will only serve to protect whatever is downstream of the can i.e. the turbocharger compressor. Which is a Point I have already made several times.
Also, how many experiments have you done to determine the effectiveness of such a metal mesh?
If you are claiming they provide a surface area, then I agree, there is a larger surface area present in a can with any kind of debris, whether cardboard or steel or sand. A potential problem with metals, is they also provides a surface for catalysis reactions. Have you taken any inorganic chemistry courses? Nickel, which is present in stainless, is a highly modifiable metal, with d-orbitals capable of bonding many chemical groups.
here are some interesting configurations for various metals (NOT catalysis reactions):
Instead of guessing, which is what you are doing without experimental evidence, I would prefer to keep things OEM or as OEM as possible. The factory did not see a need to collect anything coming out of the valvecover; there is no reason why anybody else should, unless it becomes necessary or desirable. Such as in the event of wanting to protect your $2000 turbocharger from oil. Which is a point that I have made several times, a valid purpose for a catch can. Certainly not missed; I even posted a picture of it in action.