How to stop Returnal FPS from dropping 90 to 45 FPS?

Fighting alien hordes was a nightmare when my frame rate would plummet from 90 to 45 without warning. I tried enabling 'Ultimate Performance' mode in Windows, but my CPU hit 95℃ per AIDA64, which actually triggered thermal throttling and made the drops even worse. I switched to the GamePP BIOS Load-Line Voltage Adjustment Wizard, set it to L3 mode, and tuned VCCSA to 1.22V per CPU-Z. This worked perfectly; frame times stabilized at 9-14ms per RivaTuner, while core temps sat at 75-81℃ per AIDA64 and GPU at 68-75℃ per GPU-Z.