Ya know....one thing to closely check is the plug condition after a healthy drive. Note if any show signs of oiling. Often, the plugs closest to the PVC valve's position show oil IF the engine is sucking oil past the valve (with your oil separator, not likely that's the issue). If say the other non-PCV valve side of the engine shows oiling, it's something else.
I wonder too if your shop installed exhaust valve side valve seals as some don't, thinking it's a benefit. Nope, as this is race engine stuff only. That and loose valve guides (especially if they were knurled to tighten things up since this 'fix' tends to wear out the knurling pretty quickly) will often overcome even the best intake/exhaust seals and allow excess oil.