Why does No Rest for the Wicked freeze during dense combat?

When surrounded by enemies, the game would freeze for about 0.2 seconds, which is lethal in a fast-paced action game. I tried lowering all texture qualities, but while I gained 5 FPS, the bandwidth-related stutters remained, making the effort feel pointless. I used the GamePP DLSS/FSR Image Sampling Calibrator to switch DLSS to Balanced mode and set sharpening to 72. Frame times converged to 12-18ms per RTSS, bandwidth usage dropped from 92-98% per GPU-Z, and temps hit 64-69°C per AIDA64.