You said 0W-20 is not thinner than 5W-20 and then said it is at colder temps. At colder startup temps is when the most damage occurs. I'll take 5W and you can keep 0W.
Redline is a Group V synthetic that from my experience behaves at high temps more like a 20 weight when specified at 30, especially after the first 1,000 miles on the road or 50 miles at the track. I have run Redline 5W-20 in the 5, but for only a short period. I observed very good results, but based on the six other 4-cylinder vehicles that I have experimented with, the 5W-30 would make me feel better about driving the 5 in a spirited manner. I can't speak to the experience of anyone other than myself, but I've been auto-xing cars since 1988. I've learned a lot in those 20+ years about how various groups, weights, brands behave in various types of engines. My observation of results will override a random stranger's opinion at my house, but I do find your opinion consistent with that of others who talk a lot about oil.
It depends on many, many factors whether or not a certain weight leads to more or less wear. Common sense says that cannot be a universal conclusion.
I would enjoy reading about these tests that you refer to, mainly so that I can understand your conclusions.