From my experience, the biggest contributing factors to overall sound quality with the signal leg of an IC cable are material and geometry.
Geometry that reduces the skin effect seems to work best, the D1 and D2 IC cable's signal wire is made of ~166 individually insulated strands of 44 gauge UPOCC copper... it is a litz cable developed for audio use. Litz wire was originally developed for RF applications and is intended to eliminate skin effect.
Duelund and others use a different approach, they use a flat wire or foil type geometry that reduces the thickness and increases the surface area of the conductor.
So in some of my cables there is one strand (DD) and others (D1, D2) have ~166 separate strands. Both work great. So I suppose I don't agree that fewer strands are better. There are far more important factors and using a single strand of wire with a round cross section is never going to provide optimal results imo.