I think the win 10 features menu was set up to differentiate between the way the PC boots. In many old Gigabyte boards, the feature was called Win 8 compatibility Mode but what the modes did was set the BIOS up in UEFI boot mode.
Now that most new boards only support Win 10, that mode is removed because its the standard method of booting and its likely they have a new mode added called CSM (Compatibility Support Module) or Legacy, for people who want to boot other operating systems that still use Legacy boot method (like win 7 not that it will work well on a motherboard which only has win 10 drivers)
UEFI - New boot method used by Win 8 & 10, supports GPT drives
CSM/Legacy - This was the boot method used by all windows PC prior to Win...