Just got my 5th zte pro , I'm getting closer, lol but I'm not expert on the adb commands , but learning , also my attempt in the pass , also for full adb commands I learned that with the phone off and holding the volume up while connecting to my laptop has all fastboot commands down to a t which why I'm on my 5th lol but also holding the volume down and up connecting to the laptop is seen by adb but limited, going to see what the volume down does , and try the fastboot oem unlock bootloader , and a few Samsung unlock bootloader codes, I highly doubt this zte has htc procedure, just a command to unlock… wish me luck