Good read. I think for anyone creating so many ideas and want to test, it is safer to try landing page method. 100 ideas, 3 really gets traffic, then those 3 really work.
Yeah, I think the key point is that the landing page method is great for identifying smashing successes (high true positive rate, low false positive rate). But ideas that fail the landing page method might still be good, just need more investigation (high false negative rate).