[Android Q&A, Help & Troubleshooting] enduserdeveloper:
successful flash unlock

i was able to unlock my bootloader sucessfully using flashing unlock method on 7/27/18, build RCT6973W43-ANDROID6.0-V27-V1.16.130-DS-E08. after a few trip ups on the flashing confirmation screen i realized that on the first flash, cancel was highlighted and by holding the vol up button switches that selection to yes. i found this is the easiest way to invoke the unlock correctly:

1. install all drivers needed for adb connection to tablet

**After this next step, it gets a little intense so read ahead a few steps to prepare before entering the command in step 2.**

2. type this into cmd prompt in windows: adb reboot fastboot&&fastboot flashing unlock.

3. as soon as the screen on the tablet goes black, start holding the vol up button.

4. when the screen flashes, release the vol up button and immediately start holding the power button.

5. On the second screen flash, release the power button and this enters your selection.

the cmd prompt will cycle through a couple of scripts, then it will display this message:

OKAY [ 77.430s]

finished. total time: 77.430s

then, type this cmd into the prompt:

fasstboot getvar all

this is what my output was:

(bootloader) version-baseband: 24848

(bootloader) version-bootloader: BOOTCORE_VER

(bootloader) product: SF_3GR

(bootloader) secure: NO

(bootloader) unlocked: YES

(bootloader) device_state: unlocked

(bootloader) off-mode-charge: 1

(bootloader) ========== parition type ==========

(bootloader) system parition type: ext4

(bootloader) userdata parition type: ext4

(bootloader) cache parition type: ext4

(bootloader) hypervisor parition type: raw

(bootloader) boot parition type: raw

(bootloader) recovery parition type: raw

(bootloader) splash parition type: raw

(bootloader) mvconfig parition type: raw

(bootloader) secvm parition type: raw

(bootloader) vrl parition type: raw

(bootloader) psi parition type: raw

(bootloader) slb parition type: raw

(bootloader) ucode_patch parition type: raw

(bootloader) (null) parition type: raw

(bootloader) (null) parition type: raw

(bootloader) (null) parition type: raw

(bootloader) (null) parition type: raw

(bootloader) ===================================

(bootloader) ========== parition size ==========

(bootloader) system parition size: 0x00000000d0000000

(bootloader) userdata parition size: 0x00000002a6300000

(bootloader) cache parition size: 0x000000001a900000

(bootloader) hypervisor parition size: 0x0000000000400000

(bootloader) boot parition size: 0x0000000001000000

(bootloader) recovery parition size: 0x0000000001000000

(bootloader) splash parition size: 0x0000000001700000

(bootloader) mvconfig parition size: 0x0000000000100000

(bootloader) secvm parition size: 0x0000000000c00000

(bootloader) vrl parition size: 0x0000000000040000

(bootloader) psi parition size: 0x0000000000020000

(bootloader) slb parition size: 0x0000000000100000

(bootloader) ucode_patch parition size: 0x0000000000003000

(bootloader) (null) parition size: 0x0000000000020000

(bootloader) (null) parition size: 0x0000000000020000

(bootloader) (null) parition size: 0x0000000000020000

(bootloader) (null) parition size: 0x0000000000020000

(bootloader) ===================================

(bootloader) ========== has-slot ==========

(bootloader) system has-slot: no

(bootloader) userdata has-slot: no

(bootloader) cache has-slot: no

(bootloader) hypervisor has-slot: no

(bootloader) boot has-slot: no

(bootloader) recovery has-slot: no

(bootloader) splash has-slot: no

(bootloader) mvconfig has-slot: no

(bootloader) secvm has-slot: no

(bootloader) vrl has-slot: no

(bootloader) psi has-slot: no

(bootloader) slb has-slot: no

(bootloader) ucode_patch has-slot: no

(bootloader) (null) has-slot: no

(bootloader) (null) has-slot: no

(bootloader) (null) has-slot: no

(bootloader) (null) has-slot: no

(bootloader) ===================================

(bootloader) max-download-size: 0x3bb00000

all:

finished. total time: 0.328s

Now I am off to try flashing this beast lol. if successful, I will come back to this thread with more information. Hope this helps someone.