When I’ve been involved in deep disagreements with someone I usually go the reductionist route - i.e. trying to find the fork in the road between our beliefs so as to find the common ground before it.
In this case, I suggest the most productive conversation would be about how to scientifically prove cables matter. Whether listening tests or some form of measurement...whatever...but if we can’t even agree on a method of proof, this will go on forever.
I’ve found that quick switches in the audio signal, like you’d have in a double blind, may be somewhat effective in detecting differences, but unless one of the samples is truly bad, I have found that these quick switches do not tell you which is superior. It’s often the case that hot treble sounds better at first but is fatiguing.
This happens to me often when I switch gear. An immediate improvement is detected but in the long run the other was better, or vice versa.
Long term listening is far more effective to me in terms of what sounds best. But not really effective to be able to differentiate at the snap of a finger.
In other words, audio comparisons are amazingly challenging relative to, say, comparing something visually. There is nothing to put your finger on in the same way.
Let’s fix that issue and agree on a form of proof and then someone just do it. I’m too busy but I’ll definitely watch 🍿