You can force FSR 4 Redstone to work on RDNA 3 GPUs with new workaround for Linux systems — solution requires Proton compatibility to work properly

https://www.tomshardware.com/pc-components/gpu-drivers/you-can-force-fsr-4-redstone-to-work-on-rdna-3-gpus-with-new-workaround-for-linux-systems-solution-requires-proton-compatibility-to-work-properly-gpu-drivers