That's a waste of effort really. These fail so infrequently that the benefits (reduced engine temps, higher spark advance, reduced knock) outweigh the potential headache, IMO... especially on an engine which likes to go through head gaskets
. Disconnecting the vacuum lines doesn't mean the system won't vent, a broken actuator will leak regardless, a block off is the only way to fully ensure closure. Otherwise, you still need to diagnose the system if you have related problems.
You're also assuming that people who come here for help have experience with this kind of thing. Most don't have that much and as such shouldn't be encouraged to make changes they don't understand both the pros and cons to.
Pros: Reduced engine temps, better fuel economy (minimal on MKIII's), higher spark advance, reduced knock. These are all HUGE at mid-high loads when the combustion cylinder temps are the highest and the engine is more prone to knock.
Cons: If it leaks, your car will have issues at idle, possibly while it's warming up and it will cost you some power at WOT; it's not pretty; and it can be a pain in the ass to work around if the engine is still in the car... I HATE that part.
EDIT: Oh, it's not just the way things are over there... Over here it's much the same. A long time ago the old muscle car guys decided that anything they didn't understand and absolutely ANYTHING called an emissions device was bad... let's just forget the whole thing about science and 40 years of continued research and developments... Ignorance is not something to be proud of, yet it seems so many people like to wear it as a badge.