Rather clever test track and method they have composed to use to be able to measure and show the effect of Intermodulation in a same cables single (wires) configuration and in bi-wire configuration.
It is making a scientific proven difference but if it is detected by ear or not. That are determined by several OTHER factors. So audiophiles that are able to hear the benefits have some of the other factors aligned (room, speakers, gear and so on).
Used test method:
Notes
The test tone CD was played using an all in one CD player/amplifier set at half volume into a pair of floor-standing speakers. The current probe measurements were analysed using TrueRTA via a Tascam US144 USB audio interface. The single wired measurements were taken with two runs of speaker cable wired in parallel (speaker shorting pieces in place) and the bi-wired measurements were taken using the same arrangement with the shorting pieces removed. In this way both measurements used the same cross-sectional area of cable to eliminate any effect of lower resistance on our measurements.
I will paste the link again for this thread so it is easier to find than go back and try to figure out which one it is:
https://www.qacoustics.co.uk/blog/2016/06/08/bi-wiring-speakers-exploration-benefits/
There is a couple of analogies that are used in the explanation. That is needed for me anyway to be able to grasp the complex working of it. That may need to be re read and let sink in.
So we see that there is much more than some false logic that will cloud our thinking and make the individual more comfortable to put for example this specific effect aside. When it is not properly understood or known.