I would like to see some measured and audible (via true blind testing) proof from the custom cable manufacturers that things like skin effect, and impurities, and crystaline structure actually make a difference in what the human ear can hear. My belief is the build quality of the cable and interconnect solder/weld joints are paramount. For my component interconnects, I’ve always relied on Blue Jeans Cable because they make a damn good quality cable. I don’t need my cables to be sexy. Though, I will admit that if I built my own cables, or had a custom cable made, I would add a little color to the mix via sleeves, etc.
The only times I have considered a custom cable is if I wasn’t able to find a suitable alternative from the headphone manufacturer. I figure if it is good enough for the manufacturer to voice their headphones, its good enough for me.
Here is some good cable articles I’ve found when trying to decide if custom cables were for me: