It makes use of a leaked engineering bootloader, which requires you to force the target device to boot to the Qualcomm SoC’s Emergency Download Mode (EDL) and perform several low-level flashing jobs.

The underlying concept of this method is pretty much like the one used for the Sprint LG G8 ThinQ bootloader unlocking process, minus the initial part where you need to gain temporary root access using an exploit. In a nutshell, the new method doesn’t require a specific firmware, and it is even compatible with the Verizon variant of the LG G8. The engineering bootloader essentially puts the devices into a state where they are capable of accepting the regular fastboot oem unlock command without a token generated from LG’s official unlocking server.