First,
The renaming of the Boot folder and the edits to the Plist should have worked or so members say... I have not tried this.
Second
I would stay away from Kaby bios updates which are the 20 series, there is an F4 bios release; 3/21/2016, which has the same feature updates as the F5e beta bios for my GA Z170mx Gaming 5. There is a site with newer beta bios(s) but they are not fully tested and are only for the Z170 chipset boards. If the F4 bios does not cure, then you will have to go to a 20 series bios and make the required adjustments.
Third: there is a bios update tutorial by Stork which is written primarily for a Mac only PC. Personally I would download bios on a windows machine, and use 7 zip to unzip. You can do this on a Mac and unzip with builtin utility or stuffit, but working with a PC file on a Mac opens you to possible problems, as the bios is what makes you PC run, and run right, since it was not written in MAC code, staying with the same OS the bios was written for, is safer. You can then copy to a flash drive, unhook all os drives from board temporarily, go into current bios, then built in flash utility section, it will detect your flash, point to bios update file, and pray alot.
https://www.tonymacx86.com/threads/how-to-update-your-gigabyte-motherboards-bios.131047/
Forth,
Why this whole instruction set in a "Toledo" (outline form), is not in the current install instructions, is the mystery of the year...???