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%