Here is my experience.
I had no screen shadow or burn in on stock for more than 6 months. I decided to root the phone and bam I got the screen shadow. I had to set RGB colors to 91% each or 233 of 256 and that works every time (EX kernel). Any higher and I'd see very light screen retention.
I had some battery issues recently and wanted to test stock kernel again to see if it is kernel related. So I went back to stock without locking the bootloader also in the hopes that it would fix the screen retention. The screen retention is still there.
I am using two apps from PlayStore to fix it on stock:
ScreenAdjuster and Bluelight filter for eye Care. They both work and I like the ScreenAdjuster better. Can't really tell there is a difference in contrast while for the latter (Bluelight) there is a small tint. Set all the values to 5% and have it start on boot. (For Bluelight you need to set it to 6%and pick the dark grey). Then hide either app from notifications and menu. Use only one of these of course.
The screen retention with any of these tricks will go away after about 10-15 min or reboot.
Before my warranty runs out in October, I will lock the bootloader and try to get it repaired.
PS: my battery performance is only slightly better on stock and I will probably go back to Invicta soon. I miss substratum.
Edit: kunalgupta1, anytime the values go back to default, the screen retention comes back over a few minutes. As long as it is set to 233 it will be gone.
Cheers
