Never tested anything.. never had an issue and that was the third custom sata power cable I made.
I installed the drives, put the plugs in an laid the wires on top.
Starting from the bottom drive, I pushed in all the wires all the way using a flat screw driver tip.
Then I made sure the wires were all stretched between plugs before I continued with the next, and so on.
Last time I used a different cage where it was possible to sleeve the cables, but that was a real pita! (Never again)
Besides, I spent half an hour filled with swearing and followed by massive ly hurting fingertips this tuesday when I installed the cable combs on atx and gpu cables.
I can say that, while the combs are very sturdy, they clearly weren't intended for mdpc-x sleeved cables..
One of the atx combs didn't "make it" through completely intact and now I'm not really happy...
Will take some pics next week because it's still better than the wild chaos it was before..