Amirm, with all due respect, just tell me WHY you did power cord listening comparison on a device with SMPS? I refuse to believe that you did it on purpose.
Could you repeat the comparison with a DAC (like d70s or other with traditional PS) and say honestly that you hear ZERO difference? I know you have traided ear, that you can tell the difference between mp3 and wav. I just do not believe, that you will not notice the difference. And it is not just our "mind focus" that makes it. It is objectively real. I'm sure you could measure it somehow, for ex. 15kHz square wave or some other tests (but not with 1kHz test tone for sure...)
Audiophile power cords stem from the times where switch mode power supplies were VERY rare. Simple, traditional PS were more common. Today expensive power cords become more and more stupid, I agree.