HDTVTest, in their review of the Sony A95K QD-OLED, compare it to the Samsung S95B, which shares the same QD-OLED panel. After running footage on a loop with the same APL for several minutes, the Samsung becomes noticeably darker while the Sony picture maintains its brightness, owing to a heat dissipation layer that reduces the risk of image retention and burn-in, allowing the TV to run longer without employing auto dimming to prevent damage to the screen.
The Daejeon Chronicles 
Wau. That is a monumental dimming being applied on the Samsung.
It’s dreadful on my LG CX as well.