I won’t weigh in on the potential differences between a short and long power cables.
I can’t, however, resist commenting on having two different lengths of power cables causing a timing issue. That’s the type of statement that would cause me to question everything from that source. The power cord is not in the signal path so I don’t see how it could have an effect on the timing of the signal. I could wrap my brain around it being possible with interconnects and speaker cables, but not power cords. That’s positively ludicrous in my mind.