Steam Deck: An Actual Guide to Enable FSR

OS Side:

Press the "..." button.

Go down to the "Performance" tab, looks like a battery.

Scroll down to "Scaling Filter" and go all the way to "FSR."

You can leave that on 5 for now but go ahead and play around with it later.

Games Side:

Just a quick note, some games might not be able to utilize this. For example: Metal Gear Rising. You don't need it for that game anyway.

Goto your graphics settings.

Resolution and go down to 720p. It also all has to stay 16:10.

Now goto "Screen Mode" and put it either "Borderless" or "Windowed" for FSR to even turn on.

Kinda helped with performance for Temtem, doesn't seem to stutter as much now. 👍