ok, i see where i'm getting confused in the first place.  Diffuse isn't in sRGB space in the first place.  Diffuse is linear calculation, like everything else render based.

so not linearizing the original but correcting the the result is: (color * Diffuse) ** 1/n

but linearizing first is: ((color ** n) * Diffuse) ** 1/n

which is equivalent to : color * (Diffuse **1/n), but not (color * Diffuse) ** 1/n.