The 3D Fog (exponential) effect must be depth-based (i.e. a plane perpendicular to the camera direction) because, especially at wider FOVs, you can get very unnatural looking drop-off of the fog at the edges of your view due to it not curving around.
Is there any way of adjusting the effect to be distance-based instead to avoid this issue? Or has someone, by any chance, already created a modified version of the effect that does this?