Why does Metaphor: ReFantazio stutter in crowded urban areas?

I felt total anxiety exploring the city; the frame rate would plummet from 90 to 40 FPS whenever NPCs crowded around. I tried increasing virtual memory to 32GB, but it didn't stop the stuttering and actually made the system feel sluggish. I used the GamePP BIOS Load-Line Voltage Wizard to tighten VRAM timings to 36-38-38-72 and bumped voltage to 1.25V per GamePP voltage tool. Now, latency is a smooth 68-74ns per AIDA64, and MemTest86 confirmed zero errors over 4 passes with 64-70℃ temps via GamePP.