Not that I need it, just interested, because everything else has black to white spectrum which is like a mask for adjustments but normals look funky and unusable.
I know the normal pass can be used to adjust lighting effects after rendering. I've also seen it used to apply different textures to models after rendering.
Personally I've never tried these methods or needed to make the adjustments I described after rendering. It's a powerful render pass but advanced in its usage AFAIK.