How to fix random frame drops in Judgment's city areas?

While strolling through Kamurocho, the frame rate irregularly dropped from 100 to 60, making it feel clunky. I first tried lowering the frequency to 6400MHz in BIOS; while the drops stopped, the average FPS decreased by 5, which was an unacceptable compromise. I used the GamePP BIOS Load-Line Voltage Adjustment Guide to raise SOC voltage to 1.22V via HWiNFO and fine-tuned tRFC timings. AIDA64 tests showed latency stabilized at 62-68ns and temps at 58-64℃.