I came across videos from a few years ago by Ethan Winer in which he demonstrates his cable null tester and challenges Paul McGowan of PS Audio to a public debate:
The Null Tester
Ethan Winer challenges Paul McGowan to a public debate
I do not fully agree with Winer's assertion that he has to fine-tweak the tester's gain after changing to a new set of cables under test because of a "thermal drift" after his sensitive box has been up and running for more than an hour (rather, he really is compensating for minute differences in attenuation of various cables), but OK.
Not sure whether that challenge was taken on, but prior to it McGowan made a bunch of nonsensical statements in his video:
Is Ethan Winer's test infallible?
First, Winer is not null-testing power cables but only interconnects, for which his tester had various connectors. Second, Mc Gowan says that "non-electrical differences" (i.e. the ones Winer's null test does not detect) can still be heard between AC cords, specifically due to high-frequency EMI getting into the audio equipment (how said EMI is "non-electrical" escapes me). Third, he argues that there exists some kind of "interaction between inductive/capacitive loudspeaker [as opposed to a resistive test load] and the speaker cable, which is solved with different types of construction [presumably, of the cable]."
So if Kunchur claims his findings are valid and reproducible, he should give the three cables he used to Winer, who could then quickly verify the claims with his dedicated null tester (not that we do not trust the AP).