confirmed that I have unlocked my t-mobile bootloader also. TRY THIS AT YOUR OWN RISK!!!!
booted into fastboot mode by
a) powering down the device
b) putting the cable into the PC USB drive
c) hold down - volume down button, insert USB-C cable into the phone.
d) check the USB drivers in device manager.
e) I manually installed USB driver using the google USB drive from SDK tools 2.2 (LG drivers may also work)
f) cmd, run as administrator, changed directory to my adb folder
g) fastboot oem device, listed my device (so im good to go)
h) [FONT="]fastboot oem unlock (doing such will erase your phone)
I) fastboot getvar unlock[/FONT]
j) fastboot reboot
device boots with security warning (ie bootloader unlocked), boots fine, clean device
went back into fastboot tried to compile a basic TWRP using my v10 TWRP as a basis....fail on my coding skills ( I am still learning)
using command fastboot boot XXX.img
c:\adb>fastboot boot v20.img
downloading 'boot.img'...
OKAY [ 0.700s]
booting...
FAILED (remote: unknown command)
finished. total time: 0.721s