That's for Maxwell cards, it was possible to edit BIOSes with the previous gen GPUs. Not gonna work with Pascal.
I RMAed them
too much time spent on faulty cards/mobo
If you've had the same problem with all the cards in the rig and not just 1-2 of them, then you're most likely doing something wrong. Or it's an issue with the motherboard. Why did you even try to flash your Colorful cards with the BIOS from a Gigabyte card? What's the point?