There should be an option to disable Screen Space Global Illumination and SSR reflections.

[KingKrouch]

As far as I'm aware, the lowest graphical settings still has these effects enabled, and at least on the Steam Deck or a system with a fairly low resolution, these effects in Unreal look butt ugly with no way to turn them off (at least since the developers removed the ability to use custom config tweaks). SSAO is likewise a bit of a mixed bag with low resolutions.

It would be nice to have an option to disable them, as they create a bunch of necessary noise in the image quality, and they do have a performance impact.

Also, as an FIY for those playing on the Steam Deck, install this game on the SSD and turn off game recording. It will improve your framerate by quite a bit, while having it installed on an external HDD causes abnormally long loading times.