So why did you say that this was an issue with no evidence?
So basically ********. Why is it that all these """experts""" can hear the difference but can't pull it off double-blind and can't quantify what it is that could make an audible difference?
And rule #1 is that you don't need any data to prove one design or material is different from another, you just need some opinions.
The "challenge" is to put your money where your mouth is and go out and prove you can hear the difference between class A/B and class D amplifiers. You have claimed they somehow will sound different but haven't provided any evidence. Not RTA measurements, not O-scope readings, and certainly not evidence of people consistently being able to hear the difference double blind.
You're the one making some wild claim here so the burden of proof is on you.