Kind of on a related note, I was trying to clean up my cabling, and I have several lengths and kinds of balanced IC’s, most of which I made from DH Labs pure silver wires.
I wanted to go from a 2m pair to 1m, of the same kind. When I did, the left side was just a little low. Probably less than 2 dB. I replaced them with a pair of WW Eclipse 7 Gold I wasn’t using which were the right length. I had gotten frustrated with the huge connector sizes in a previous cabinet, which led me to DIY a lot of my cables.
Anyway, the WW 7 fixed the problem, I clearly have a fault in the DIY cables.
My point is, honestly based on buyers I have seen at stores sellers convince to spend $2k on a power cord, 95% of them would never have noticed this.