Thanks for the suggestion, Dan. I am running a vanilla P3D 5.4, default aircraft, default airport (in the middle of nowhere, not a "heavy area"). Tried those numbers for JobScheduler as well, no luck. Rarely below 80 degrees centigrade. I am running 4k (60hz) though, I don't know if that has anything to do with it.
What I find strange is, that if I lower the "texture resolution" slider from 7cm to i.e 5 meters, my CPU cools down immediately. I find that a bit strange because I thought that would only affect the GPU.
Anyway, I guess the time has come for me to remove P3D. I will miss the FSLabs bus 😢