As I'm now staring at the "CableMatters" mini-DP-to-DP cable between my MacPro and my 40" 4K monitor, and the CableMatters USB-C cable was on the "fail" list.

So, yeah, where do I get a properly compliant mini-DP-to-DP cable? Am I going to fry my MacPro? That would be a barrel of monkeys when I tried to exercise the 3 year AppleCare warranty.