How to fix Fortnite stuttering on Western Digital SN850?

While descending fast in Fortnite, I hit weird stutters—completely unforgivable for a high-end NVMe drive. I excitedly enabled 'Extreme Cache' in the driver, but while sequential speed rose, random access latency increased by 6ms per CrystalDiskMark. I used GamePP NVMe Queue Depth Configuration to switch to 'Extreme Performance' mode and set the depth to 128. HWiNFO64 showed read latency dropped to 12-18ms, and AIDA64 confirmed temps stabilized at 48-55℃ after fan curve adjustment.