[LG V20 Questions & Answers] Buzzy42:
I recently bought a refurb VS995 because I like my original VS995 so much and I am thinking that shortly after the Oreo upgrade comes out, any refurb might come with Oreo and may or may not be easily rootable. (and it is looking very unlikely any phone in the future will come with replaceable batteries) That said, mine came with 15A and I was easily able to roll back to 12A with the 'hacked' LGUP tool and then root it and flash the at-the-time current AlphaRom (now discontinued) without issue. AFAIK *all* current VS995 ROMs can be rolled back to 12A (rootable), up to the latest 1BA. This may or may not change soon (some versions of the V20 CANNOT be rolled back after they take specific updates) The SuperV20 ROM is running the almost up to date version 1AA (with hints of an update coming soon) so you'd be up to date with a close to stock ROM. I will say the rooting process on the V20 is a bit more convoluted than most other phones, which leads to the issue that the rooting threads are nearly incomprehensible anymore-- too many people not following directions, not reading, and complaining about tons of "normal" issues-- static screen (normal after rooting with stock kernel, once the phone boots up fully cover the proximity sensor until the 2nd screen blanks out and then the static will go away-- replace the stock kernel with the mk2000 kernel to fix), phone vibrates on boot after charging (no fix, but will stop the first time it's made to vibrate after booting). I would stay stick to the original rooting thread and READ CAREFULLY. I had issues trying to follow some of the "updated"/new threads where I had issues trying to get the phone to boot properly.

That said, if you do hit a roadblock, DON'T PANIC. The V20 is more resilient than you might think and you can almost always get it back from soft bricking with the LGUP tool (I had to reflash mine 2 or 3 times before I finally got root to stick with the ORIGINAL DirtySanta thread). Basically, the process is flash it back to 12A, use DirtySanta, **boot it once or twice after getting root via DS** (first reboo.t may take a while, with a static screen and vibrating phone, let it sit 10-15 minutes before panicking as it's rebuilding the app cache), then get into TWRP, do a factory reset, flash the new ROM and BTTF kernel, then it should work.

The VS995 has a more limited LTE band selection than the US996. While it can sort of work with other carriers (you'll have to search for instructions/compatibility), the US996 will provide a better experience.

Keep in mind, each version of the phone is SLIGHTLY different, so MAKE SURE you're always using VS995 builds of ROMs/kernerls/recoveries. Apparently you can use US996 ROMs as well but I've never bothered. (you gain a few things, you lose a few things [like wifi calling I think], do your research) Trying to use anything other than VS995 or US996 roms is asking for trouble/limited functionality/soft bricking.

I haven't really used my refurb all that much but it seems mostly fine. The only glitch I see is that the battery seems to drain faster than my original V20 but that might have more to do with the battery condition-- I need to get around to swapping batteries between the phones to see what happens. Given everything else is fine I am very hesitant to return it under warranty. I don't know if there is a way to run a self-test, I would hope there is..!

Good luck, the phone is amazing once you get it tamed...

Links:

Downgrade: the VS995 "all in one" thread has a good video for this. That said I think I had to piece together a working LGUP from a few threads since you need a tweaked DLL file. https://xdaforums.com/v20/how-to/lgv20-vs995-verizon-aio-post-06-19-2017-t3624326 (when I tried to follow the root directions in that link I had issues and had to re-flash 12A and start over, YMMV)

DirtySanta: https://xdaforums.com/v20/development/ls997vs995h910-dirtysanta-bootloader-t3519410

Once you get a working TWRP from DirtySanta, update it to this one: https://xdaforums.com/v20/development/recovery-twrp-3-2-1-0-t3720239

SuperV20 ROM: https://xdaforums.com/v20/development/rom-superv20-h918-t3764390

mk2000 kernel (I'd use the "back to the future" version of the kernel to start): https://xdaforums.com/v20/development/h918-h910-us996-ucl-mk2000-kernel-t3708330