Yes, the hard part of a web search is figuring out which bits of data to believe 'cause you will almost certainly get conflicting results. I try to read several posts from the people whose comments are the most significant as sometimes I get a sense from them of whether or not the person knows what he's talking about. And, I'll admit that I'm biased - I sometimes base my beliefs about a poster on the way s/he writes, spells, and uses grammar - or doesn't.

I do agree that the engine should warm up more quickly with the valve open as there would be flow. Otherwise the once-hot gas would cool as the air/fuel mix passed through. But, I also agree that the valves look to be prone to sticking. Mine is so sooty that it is hard to believe it would work. And, we all know that EGR valves stick, either from the heat or carbon or both.

However, I've recently been told on this forum by Franklin2, a very well-respected gentleman, that you should not block off the heat passages completely. He's tried it and said the driveability suffers badly.