I’ve used doubled up Audioquest Type 8, and then Audioquest Gibraltar where there is “optimization” for high and low frequencies.
Many people I know who understand far more than I do about electronics and noise (including a physicist who was PM of the first LIGO construction) say that biwiring should not make a difference. But, like so many things in audio, it does, at least to my ears. I have done the experiment enough times that I have convinced myself, and Bill Low certainly agrees.
My formal electronics training was taking and auditing a year of electrical engineering for mechanical engineers at UC Berkeley (I was a grad student in Geology helping to build some lab measurement systems), taking a bunch of BS Physics major courses and labs as an undergrad, and have experience helping design and build laboratory equipment used on the JOIDES Resolution scientific drill ship and in other geology and chemistry labs. I’ve also built and modified audio equipment earlier in my life. Oh yeah, Thevanin equivalent, now I remember!