Please read carefully and thank you.
Okay, but remember, A-O 10V is already on the phone. So I'm asking, will it flash okay over a firmware that's already at 10V ?
I thought you couldn't go backward. Will it overwrite the A-O files? Or do I have to start from the beginning again so that I'll be at an earlier point (10E) before I flash 10R ?
Posted from my way cool LG V20 (H910) Nougat 7.0
The A-O_4.0_H910.zip does not contain any firmware ... it's only the system folder pulled from 10v source
the 915 kdz flashed many partitions that are still on the phone because you never flashed a Full H910 firmware
the proper way out of where you are now is
boot to TWRP and update TWRP
flash the 10r rom ( it includes all the H910 firmware and gets rid of the leftover 915 stuff)
setup your new rooted phone
Edit: the 10r rom is not mine it's part of the Guide
Also it seems you missed everything in the guide after STEP3.bat .. read it again
This is flashing TWRP and the WW 2.0 kernel onto your phone. The phone will reboot once they are flashed.
When it reboots, you will get a very nasty looking warning about the fact that your phone has been compromised and will not boot.
This is due to running the engineering aboot and is normal -- don't panic your phone will boot. You will see this every time the phone reboots.
At this point, you have H915v10e and TWRP. You can now boot into TWRP so that we can flash the H910 firmware back onto the phone:
If you have re-enabled developer mode, and enabled USB debugging, and have your phone connected, you can execute the following in a command window:
adb reboot recovery
Otherwise just pull the battery, put the battery back in, hold vol down + power till the LG logo appears. Release power, and then immediately press and hold it again until you get to a screen that asks if you want to factory reset your phone. Say yes twice and it will take you into TWRP. If the phone had the stock recovery, it would do a factory reset -- however, since you now have TWRP, that is what you are taken to instead. This is a key combination that is embedded into the bootloader that tells it to execute recovery - in this case TWRP. Hope that clears up some confusion as to why you get a screen asking you to factory reset your phone...
Now that you are in TWRP you need to do a couple of things:
Format data. Wipe -> Format data. It will ask you to type "yes". If you don't do this, you will be prompted to enter a passcode, and will have 30 tries. If that happens, just boot back to TWRP and do this step again.
Wipe cache / dalvik cache
Flash the zip. Choose "Install" and browse to your SD card, and select the h910-10r.zip file. When complete hit the home button.
Now, format data again for good measure....
Once the second format completes you can reboot your phone, and it will be just like you got it fresh off the factory floor, except it will have TWRP.
No part of the H915 firmware is left on the phone. The only things that are not 100% stock v10r firmware are ABOOT (it is the US996 engineering aboot that is unlocked. It also gives the nasty warning on boot), BOOT (it is the 10q kernel with a few patches added by @askermk2000 - KCAL, Adreno idler, etc), and of course RECOVERY (TWRP).
It takes a little while for the first boot -- be patient. It should NOT take longer than 10 minutes. If it does, something went wrong. Boot back to TWRP and try flashing the 10r zip again.
Now that you have a phone with TWRP, feel free to download whatever root method you would like (SuperSU or Magisk).