only issue i have with his testing method is he never tests in actual use just isolated on his tester / bench. so, he won't see interactions of the components and how they affect each other just the raw test of the single component / cable. No interaction of a speaker cable to the amp and speaker for example. no indication of issues with a component not liking the impedance or capacitance of a cable etc. Testing in isolation is only part of the story.
Other than that, it's just more information to make an educated assessments prior to listening for yourself.