How can I fix blurred character faces in Dying Light 2 Stay Human when using DLSS Quality mode at 4K resolution?

Character faces looked like they had a soft-focus filter, losing all beard detail. I tried Balanced DLSS, which made the blur even worse. I used GamePP DLSS/FSR Image Sampler Calibrator to raise sharpening from 50 to 75 and set render resolution to 100%. GPU-Z showed temps stable at 55-61°C. RivaTuner confirmed the textures became sharp again. This switch restored the intended visual fidelity perfectly.