I have been working on european cars for 20 years, and starting in the mid to late 90's all the euro manufacturers started using a crankcase pressure regulator similiar to the one in our m96/m97 engines' AOS. I have replaced many of them, and I broke apart many of them, at first to see what was going on inside, but I still do to verify that I have isolated the problem in most cases. there is a rubber diaphragm with a spring against it that together regulate the amount of vacuum applied to the crankcase. when sufficient vacuum is achieved the diaphragm pushes against the spring, restricting the flow of air from the crankcase to the intake. when it fails, the diaphragm usually looses it's flexibility and either cracks around the outside diameter where it has the most flex while operating, or it is just no longer flexible enough to close off the vacuum. I do not know of a way to do this that will prevent failure, other than a completely different type of crankcase ventilation. I believe that porsche has a motorsport version, but I don't think it is intended to last longer, just more effectively maintain oil in crankcase. do not consider eliminating it and running with the crankcase vented to the atmosphere. it's not that I am concerned about the environmental impact, you will loose horsepower and cause oil leaks from the engine seals. one option for a track car is to use an electric air pump to evacuate the crankcase, but I doubt the electric pump would last as long as the diaphragms do. A belt driven pump(like most cars had pumping air into the exhaust for smog regulations in the 70's and 80's) would probably last a long time, as well as increasing power and relieving pressure on seals, but it would be a complicated set up to install.
I think that if you just pay attention to your car better, you can stop changing it as a precationary measure, and just wait for it to fail. I have not seen many cars that needed additional work just because the crankcase valve or AOS as porsche calls it failed. I have replaced ones that the customer had driven till the neighbors started complaining about the smoke, and although there were O2 sensor codes at the time it came in, after replacing the AOS, and driving it to clean out the pipes, all was well. Mass airflow sensors and throttle bodies are not hard to clean, and O2 sensors usually clean themselves. AS far as catalysts go, you would have to clear it all out and see if they are really damaged. I have seen ones that set a p0420(catalyst efficiency) code when the AOS has failed, or when someone overfilled the oil, and after correcting the problem and driving it to clean it out, clearing the codes and all was fine. this is with your average customer that drives it till the neighbors are complaining about the smoke. if you are tuned into your car like a porsche driver should be, you should have no problem getting it to your mechanic before any damage is done.
BTW here is a link for the motorsports part:
http://www.****************************************************.com/product/9XXSEP.html?Category_Code=986sport
at $750 though, I definitely wouldn't want to replace it until it fails.