How to fix FPS dropping from 110 to 45 in Days Gone on RX 9070 XT?

Facing thousands of zombies was a nightmare; my frame rate would plummet from 110 to 45 without warning. I tried manually undervolting in the driver; while temperatures dropped, the minimum FPS fell even further, which felt like a deceptive optimization. I then used the GamePP Power Plan Switcher to set the system to High Performance and disabled energy-saving mode. RivaTuner showed frame intervals converging from 9-35ms to 8-12ms, with GPU temperatures stabilizing at 72-76℃ per AIDA64. I can finally export