I am not so sure that LG would reject to repair or replace the panel out of warranty… take into account that OLED is the LG bet, to give a good customer service is in their best interest if they want to maintain a proper customer base.
My best guess is that LG tries their best to keep this topic out of the public. Also they already have in the user manual written "somewhere" that people should watch warried content. LG will not reject a repair, but in my case they were asking for 2/3 of the TV's price (1050 Euros) to have the panel replaced due to "burn-in". And even though I had bought and registered online 4 LG TVs they didn't care to show any sign of goodwill.
From my experience with the LG OLED B7 (2017 model) I'm pretty sure that the "burn-in" effect is cumulative.
I got the first visible "burn-in" marks after 1,5 years by using "Teletext" to read news each morning for 20-30 minutes before heading to work.
This is how the TV's image looked like after that time:
After noticing those spots I told my wife to stop using the Teletext feature and instead we switched to a morning show which has a yellow banner which again we only watched for around 30 minutes per day to see some news before work.
The yellow banner added more marks and made the available spots from the Teletext more visible. This is what the image looked like 8 months after the previous picture:
Reported Burn In Rates as of 2 April 2019 2018 OLEDs - 1.7% (out of 120 votes) 2017 OLEDs - 7.3% (out of 219 votes) 2016 OLEDs - 29.1% (out of 234 votes) 2015 OLEDs - 13.3% (out of 30 votes) Moderator note * Please be aware that the results of this poll do not represent an even demographic. By...