Why does the CPU throttle in The Witcher Remake with Valkyrie V360?

Every time I entered a dense forest, my CPU hit 90℃ and frames plummeted from 80 to 40, which was an absolute disaster for gameplay. I tried setting the pump to full speed in the BIOS, but it created a loud high-frequency resonance noise while temps still hovered between 82-88℃. I used the GamePP Fan Curve Configuration to bind the pump speed non-linearly, forcing it to 90% once the CPU hit 75℃. RTSS showed frame times stabilized at 12-16ms, and AIDA64 confirmed CPU temperatures settled at 72-78℃, while the pump held 2000 RPM via GamePP.