FSR 4 via Optiscaler

install FSR4 for AMD GPUs of the 90XX series

download the latest version of optiscaler: https://github.com/cdozdil/OptiScaler/releases

unzip into the following folder: DRIVE:\....steamapps\common\Expedition 33\Sandfall\Binaries\Win64

run the OptiScaler Setup.bat => promts should be 1, 1, 1

run the game

go to the graphics options and select DLSS

adjust the DLSS quality level to your liking

hit the insert key to open the optiscaler overlay

https://imgur.com/tmcnMzp
enable FSR 3.X and click apply
choose Frame Generation if you wish
select FSR 4.0.1
check FSR4 Non-Linear sRGB Input (optional if cutscenes get weird)
Save INI, Close

also its recommended to download this fix https://github.com/Lyall/ClairObscurFix/releases incase something breaks by the optiscaler injection - likely the cutscenes or that you cant start the game, i have read some issues.

good luck :-)