[LG G Stylo Guides, News, & Discussion] danny8:
I wish to confirm the instructions in the OP worked on my "Metro PCS" unlocked-refurbished phone purchased on Amazon. Although sold as refurbished it appears to be brand new, IMO. While I was initially underwhelmed with this phone, after rooting it my opinion is vastly improved.

In addition to confirming the OP merits, I'd like to throw out advice/opinions for anyone thinking of rooting this device.

My phone is running Android 6.0. The security patch level is 2017-03-01. Out-of-the-box I had to do several tedious reboots to upgrade the stock unrooted OS. None of these updated Android per se but I think they updated the security patches. I should have paid more attention. My kernel version is 3.10.49, build number is MRK58K, software version is MS63120p.

I'm a big fan of rooted devices in general, although I've made errors lately with a couple of inexpensive Android phones which degraded or busted these phones in some way. Not totally bricked, but software-impaired in some manner like not being able to use the Play Store or download a file. My desire to hack these phones stemmed from a need to remove junk apps like Facebook or Uber so as to free up storage for apps I actually want to use.

It seems like phones these days are locked down unless you specifically chose one from a short menu of devices with an active developer community. That's a great way to go if you have the itch to hack your phone, but I just want to scrub the stock junkware off my phone.

I followed the OP and things went fine to install SuperSU. I used my laptop and ADB connection as specified. I loaded TWRP into memory from the PC (i.e. booting recovery into TWRP) without installing TWRP and flashed the SuperSU update. Everything went fine after rebooting. I updated SuperSU, installed Ti Backup, et cetera.

I later installed TWRP to my recovery partition (I used Flashfire Pro to install this as the .img file cannot be installed via TWRP.) I used TWRP to make a couple of backups onto my SD card. I regret installing TWRP to my recovery partition, even though I'm a huge fan of TWRP. The version referenced in the OP has some irritating flaws that make it undesirable in my opinion. My first bit of advice is to only use TWRP to install the SuperSU zip. Do not overwrite the stock recovery.

Just boot into TWRP from your PC. Don't install TWRP proper.

I'm a big fan of TWRP but this version does not set the date properly. You cannot set the date manually even if you wanted to. You need to manually name your backups using today's date each time. Worse, this TWRP exposes you to a potential headache (the "your phone appears to be unrooted, want me to fix it?" nonsense) every time you run it. One moment of inattention would cost you an hour (at best) of fixing the unnecessary problem you created by accidentally swiping OK.

I might see about downloading the stock firmware for my phone if it's available. I'm not sure it is. It's not a big deal living with TWRP if I have to.

Note I did not use Kingroot to root my phone. It is not needed. My second advice is to avoid Kingroot unless you really need it. (For different phones try rooting scripts and such, but only use KR as a last resort.) If you do use Kingroot; obviate it by replacing it with SuperSU as soon as possible.

My third bit of advice is don't be afraid to unleash a bit of cash to devs who make the tools you use to improve your phone. I use Flashfire Pro and Titanium Backup Pro for various tasks. They make life easier and better. They save me time. These are just two examples; there are many worthy devs who would benefit from your help.