How to fix unstable frame rates in Nioh 2 combat scenes?

Facing hordes of Yokai, the frame rate fluctuated wildly like an ECG, creating a disastrously choppy experience. I tried increasing memory voltage to 1.4V in BIOS, but instead of stability, the game crashed after ten minutes, making me laugh at my own failure. I used the GamePP BIOS Load-Line Voltage Adjustment Wizard to set LL to L2 mode and tuned VDD to 1.35V. Memory latency converged to 70-76 ns per AIDA64, memory temperature stayed at 50-56℃ per HWMonitor, and voltage stayed at 1.35V per BIOS.