I was thinking more in general, not necessarily burn-in just from LPM (the risk there is low to begin with due to super-low brightness + can be further reduced by moving it around the screen and alternating colors). Take any 2-3 year old OLED phone and run a burn-in test (various colors + grays in full screen) and you’ll easily see burn-in effects around the non-movable screen elements (status bars and such).
I like OLEDs but it is a fact they degrade quite fast and LCDs can look nearly as striking with some clever, super-granular local dimming without that risk.