How do I fix VRAM stuttering in Pacific Drive on a Zotac RTX 5070 Ti?

Conducing through the mud, my frame time spiked to 24ms, ruining immersion. I tried closing apps, but VRAM stayed at 15.8GB per GamePP Sensor. Using GamePP to lock frequency, I dropped frame time to 18-20ms and stabilized FPS at 95-105, confirmed by RTSS.