On windows when I had NVIDIA I used DSR to be able to select 1440p and 4k in game. Is there something similar where I can render games at higher resolutions and downscale to native? I have an AMD card rx 6700 xt and I’m using Sway (wayland).
Yup. Gamescope.
The command to force a certain resolution and frame rate would look like this:
gamescope -W 1920 -H 1080 -r 60 -- %command%
The resolution configured is the one the game will see, and the gamescope window can then be resized or full screened as you like.
It can also run games at lower resolutions, and upscale them using FSR. 1080>4K looks like this:
gamescope -w 1920 -h 1080 -W 3840 -H 2160 -F fsr -- %command%