This temperature story is nice, but it's only static dyno work. Place around 20 tapes per cylinder and drive the car w/engine, where it has to live (...on the road/track/Autobahn), You'll receive more concrete measurements of the maximal heat, that is reached at nearly every point I want to measure. Ok, you can't make diagrams and you can't see it directly in °F, but what you can tell then is, that you'll have hot spots on the cylinder, where the wear is bigger, when you use the just Type 1 plate instead of the more complex Type 4 sheet metal (Besides, who speaks about using it as it comes?). Measure cylinders after a life of driving, you'll see it!
You should talk to another dyno and test fetischist in Germany, that is Mr. Rolf Klaus in person (
http://www.klaus-kaefertuning.de). He invented the underside head cooling (you can believe it or not) where cooling air streams through a heater hose to the middle of the head on the downside, to cool the engine as effective as it can be cooled...
...surely only with his Porsche style fan system.
Btw, this is definitely not my thing, but this is an example, how to develop the best of a part with a lot of tests and time, talk to him. I think, he'll still have some news for you, as he's pretty the same guy like you. Testing, testing, testing and saying (with facts on papers), that all what he builds is perfect in contrast to other tuners! Sorry, but that are just my 2 cents to that and a lot of other themes!