Why does Horizon Forbidden West drop to 50 FPS?

I can't stand the memory scheduling; the frame drops during vegetation rendering are severe on this DDR5 kit. I first tried enabling Hardware-Accelerated GPU Scheduling in Windows, but it did nothing for bandwidth and actually hurt stability. I used the GamePP BIOS Load-Line Voltage Adjustment Wizard to tighten timings to 40-40-40-96 and set voltage to 1.30V. AIDA64 showed read speeds jump from 4200MB/s to 4800MB/s, and HWiNFO confirmed temps at 44-50℃.