Non-linear adjustments seem to cause instability. Powerful GPUs can adjust these values even higher, but with diminishing visual returns. This improves the quality of all shadows in the game. MaxWholeSceneDominantShadowResolution=2688 This improves the look of textures that are viewed from far away and/or at oblique angles.
You can make these tweaks in Documents/My Games/Rocket League/TAGame/Config/TASystemSettings.ini
