My RT620P can't keep up during heavy scene loads in BioShock 4, and my CPU keeps dropping speed. Will changing process priority help?

Trying to tame this CPU with a cooler this small is like trying to put out a house fire with a water glass—absolutely ridiculous. During complex terrain rendering, the CPU hit 98℃, and the clock speed plummeted from 4.8GHz to 2.2GHz, turning the game into a slideshow. I tried taking the side panel off my case; it dropped temps by 5℃, but my PC became a dust magnet in minutes. I eventually went into the BIOS for some undervolting, setting a CPU core voltage offset of -0.05V and maxing out the front fans. In Cinebench R23, my multi-core score jumped from 21,000 back up to 23,500, with temps staying around 85-89℃. It wasn't a smooth ride—I had three random reboots before I backed the voltage off to -0.03V for stability. Now the FPS stays between 65-72, and the fans are humming along at 1400-1600 RPM.