For those that have struggled with the frozen ccv hoses...
Was helping my neighbor troubleshoot the pcv system on his beater Mazda minivan. Transverse 6 cylinder, ford design... Found the pcv hose that runs along the back of the engine completely occluded with gunk and half the hose permanently deformed to a pancake shape due to the high vacuum it was now seeing.
The Mazda dealer had a new one in stock, and sure enough the new one is more rigid and comes fully insulated, like the BMW hoses. So, frozen pcv hoses are a widespread thing, just our cars fail in a way they self-destruct by ingesting engine oil rather than simply running rough and throwing a code...