I ended up settling with this:
Option "RegistryDwords" "PowerMizerEnable=0x0;"
Seems to work reliably now!
EDIT: Not reliable, but I found something better...
Make this file: /etc/X11/xinit/xinitrc.d/20-nvidia
nvidia-settings -a '[gpu:0]/GPUPowerMizerMode=1'
Make it executable (chmod +x) and you should be good!