Dying Light 2 has plenty of graphics settings at its disposal, but there are even more settings available if you don't mind getting your fingers dirty editing a config file (as found by TheHybred over on Reddit). Along with options for tweaking the game's settings that are already offered in the game, there are a couple of extra options, such as for texture quality, clearer settings for sharpness, and the option to use AMD's Ultra Quality FSR—something that isn't available through the game's interface.
To be clear, Dying Light 2 does already offer support for AMD's FSR upscaling technology, but it only offers Performance, Balanced, and Quality settings, neglecting to support Ultra Quality through the interface. This means you can now see how good AMD's best FSR setting looks in game.
To turn on Ultra Quality, you're going to need to edit the video.scr file that you'll find in your Documents/dying light 2/out/settings folder. The best way of editing this is to open up Notepad and then drag the video.scr file onto it to open it—because it is a .scr file, Windows thinks it's a screensaver and promptly refuses to do much else with it.
Once you're in the file, you'll find the top commented-out section has a fairly decent explanation of what is contained in the file, with the actual settings appearing after the break. Notice that the upscaling entry only mentions performance (0), balanced (1), and best quality (2), but setting the Upscaling to 3 will actually instigate the ultra quality FSR option.
To get the full FSR Ultra Quality setting you need to set the following:
Save the changes and then set the file as read-only (so the game doesn't just overwrite your settings) by right-clicking it, selecting properties, and checking the box at the bottom of the window. Launch the game and you should find you've now got access to the highest quality FSR setting. You'll need to make it writable again if you want to play around some more, such as seeing what effect low-quality textures has on your frame rates.
It's worth highlighting that Techland continues to update Dying Light 2, and a patch dropped yesterday that improved DLSS quality, with more settings improvements expected in future patches as well. Check out our guide to the best settings for Dying Light 2 as well.