Why does the frame rate drop in Neverness to Everness cloud layers?

Traversing dense cloud layers caused uneven core loads, dropping FPS from 120 to 48. I tried Windows Performance mode, which improved response slightly but failed to fix the physics latency. I then used the GamePP BIOS Load Line Voltage Regulator to set LL to L3 and adjusted VCCSA to 1.25V. Per Cinebench R23, the multi-core score increased from 35800 to 37200. Temperatures dropped to 78-84°C, and I could finally backup my save files.