I had a G4 die from the bootloop problem. I went into the large red store for replacement, since there was an insurance plan on the 14 month old phone. They told me that the insurance did not cover manufacturer's defects. So I asked if I went outside and threw the phone against the wall and came back in, it would be covered by insurance? They replied it would cover the physical damage.
My ethics would not let me do this, so I contacted LG. The first time, they said that there was nothing they would do. I tried again a day later, and they immediately sent me an email with a shipping label and offered a free repair. I sent the phone in and had it back in 2 weeks, repaired for free and free shipping both ways. I don't understand why the extended warranty isn't better publicized, or why the folks at the red store weren't aware of it..
The interesting side effect of this is that I grabbed an ad-supported $99 Moto G4 Play phone from Amazon for coverage in the meantime, and have not gone back to the LG G4. While the specifications for the Moto are significantly lower, it runs a very vanilla android and the user experience is as good as the LG G4. It will run for two days under usage conditions that had the G4 going dark by the end of one day. The Amazon ads don't impact the use of the phone. And the FM radio works!! I will admit that the LG's camera is significantly better.