Yes indeed, sorry used the wrong terminology on that.Unless you meant the blow-by oil getting into pcv then yes.
Ddnspider (and i) used CRC GDI intake valve and turbo spray cleaner into the vacuum port a while back. I am not expecting it to clean everything off but the fact that I've been using catch can for a while now, occasional high temp "might" have melted away the remaining ones. I still think there's very minimal oil amount going thru though. My backyard theory tells me that just using a proper catch can one may actually not have any significant build up over the life of the engine - especially on these VRs, they blow-up pretty frequently lol!
As for the CRC GDI cleaner I was assuming it was a fuel additive, if it being sprayed into the intake than you can disregard my previous bit.
As for the catch-cans I agree based on what other forum members have reported the actual oil being captured is relatively small compared to other engines.
Although what effect and how much oil is required to start causing issues with the VR30 engine is still an unknown.