Why does MGSV cause CPU throttling during long stealth missions?

While executing stealth tasks, my CPU struggled under the weak support of the AIO, and the frame drops were maddening. I tried lowering CPU voltage in BIOS, which dropped temps by 5℃ but crashed my minimum FPS below 40 per System Monitor, which was incredibly annoying. I used the GamePP Fan Curve Configuration Panel to switch the pump to Performance mode, forcing 3100 RPM. AIDA64 stress tests showed peak temps dropped to 78-84℃ and HWiNFO confirmed a stable 5.0GHz frequency. Perfect.