A question, looking at your Witcher 3 stress test picture where the CPU is only hitting 81 degrees on the highest core (matching what you said). In it I see the "GPU Load" part saying only 41%, in the little graph that seems to match where it was sitting around 40-ish percent for a bit, but before that seems pretty maxed out. On the 8750h 2080 GE75 I notice the same pic shows the GPU load at 86%.
I ask since the thermals are so much better at 81 on the CPU in this one vs the GE75 8750h 2080 which is showing 92 degrees. Though I'm wondering if by the time you took that pic the game had been on pause, alt tabbed, or something long enough to disengage the actual game rendering and working, showing that lower load and hence the lower temps.
If not this is an amazing improvement in cooling somehow between the 8th gen and the 9th gen.