The goal here is mainly to check if it's feasible to do with minimal effort. The previous responses indicate that Mofu thinks he has to load images at their original resolution, or that upscaling or downscaling have significant performance costs.
I don't really care if any of these gets implemented, but I don't like seeing discussions based on incomplete or incorrect information.
If someone really needs to play it on their 4k tv, that person should probably just use fsr and live with the artifacts.