Rooting LG V20

Hey there! I was in a similar situation a few days ago. I also had no experience with this kind of thing, but decided to go for it and see what I turned up with. I returned the V20 to stock, but mostly because I felt that I don't understand what's going on well enough, at least for my normal liking.

Downgrading was made easy thanks to the KDZ I needed being readily available and Verizon phones not being anti-rollback enabled. I used this guide that generally automates the Dirty Santa method most of the time and referred back to the main Dirty Santa post when I was in doubt. Neither covered a particular issue around Step 3 I had where the phone was not detected, but I figured it out after a little Googling for the general issue. After all that, I had a bootloader unlocked device and was able to flash SuperSU (not Magisk directly, and I still don't quite know why). Then I flashed the Alpha Omega ROM.

It was after flashing the ROM I realized that I was a little in over my head, because issues I knew could be fixed (like the fingerprint sensor not working because of a modem issue) were unsolvable to me. Yes, the phone was running and charging better, not to mention the screen retention being solved, but I like knowing what's going on and understanding the process more than that. So I grabbed the most recent KDZ and put my phone back on stock.

I'm gonna give taking control of my V20 another shot some time in the future, but I need to learn more about the basics of rooting and bootloader unlocking Android phones first. Then, hopefully, I can fix the little issues I have with the V20 and make it nearly perfect for me.

Oh, and to address other concerns I see in here, the second screen still worked fine when I flashed Alpha Omega. Battery life wasn't particularly different (this issue is addressed in Dirty Santa and some ROMs, follow directions carefully just to make sure that wasn't it!) in my case at least. As for the bootloader warning thing, yeah, that's pretty annoying. I don't think any other model than the VS995 (yay for me) vibrates during the entire startup process though.

If you are gonna root, you should flash SuperV20 or similar custom firmware too. If you are just going to root your phone without any custom firmwares, my advice is don't root it. According to my experience, rooting the phone caused major battery drainage and every time when you boot up your phone, it takes awhile to boot showing you the "your device is corrupted" which is annoying and also you do need to keep in my that your bank related applications will not work plus you will lose access to your second screen.

Edit: I am not quite sure whether the second screen works now when you are rooted since I attempted to root my V20 awhile ago

I'm in the same boat actually. There's a dirty santa root method topic on xda that was quite an overwhelming and convoluted process just to read the other day. Also, iirc, magisk can hide that you're even rooted so banking apps and such will still work. I replaced my thermal paste the other day and despite lower benchmark scores the phone is smoother even without factory restoring it. This v20 apparently NEEDS a custom kernel as it likes to throttle, and LG root checker needs to be disabled as it'll constantly be eating up the phone's resources. Using the custom kernel tho in theory would make battery life quite a bit worse than this phone is already known for as the CPU will be at full throttle at all times. Definitely seems like a double edged sword. This definitely seems to be a tinkerer's only phone the more and more I read about it all....as an average Joe that isn't a custom ROM type of person and just wants something smooth with good battery life it seems like this wasn't the best choice:/

If you're looking simply to freeze/disable programs there are programs that can do this without root.

LG Package Disabler can do it. It may cost a few dollars but it works. I haven't had any problems using it on the v20.

Obviously if security is a concern then you might do the root route instead since the program works via Administrative privledge.