Another random observation regarding the feasibility of a cable test:
Everybody professionally employed to record music or deal with its technical rendering is so damn busy that these kind of fringe issues fall quickly under the rug:
An inventor had sent me a "new technology" guitar cable a month ago, with a long handwritten note, lovingly composed and executed.
Have I had time to sit down and evaluate this cable in the manner the gentleman deserved? Have I tried it on several amps, with several volume settings, clean, distorted, several guitars, different pick up topologies?
No. I quickly plugged the cable in before a recent gig, decided that it was not thrilling me enough to take it to the gig, packed my trusted Belden rubber cable instead, and have not spent any time since with the new cable to analyze its merits or lack of.