I’m having the same problem. When powering my Pi 3 B+ together with PiDrive 375GB with original WD 3A power supply, Pi doesn’t even boot. It get’s stuck at the rainbow screen and is showing the lightning bolt while the red LED is blinking. I have only connected a keyboard via USB and monitor on HDMI.
So I would be happy to also test the low resistance cable if it helps.
BTW: If it is known for about a year that the cable is a problem why is the same cable still shipped out? I have received mine yesterday.