Limiting FPS in NVCP has never worked for me either!
Get Rivatuner, it’s rock solid. Does the Pico4 run at 90hz? If yes, definitely cap at 45fps.
Basically always try to cap at exactly half the refresh rate, assuming you can’t reach that rate of course.
45fps feels amazingly smooth on the G2. Much more so than 30 or even 50. It’s literally day and night.