I'm also using a kind of "artificial" light intensity which makes this term stand out even more, am I wrong in doing so ? (I do this to produce a strong light source e.g. direct sunlight).
// Incident irradiance float4 Ei = _LightColor * _LightIntensity; // Lambert float3 kd = NdotL; Lr.rgb += (kd / PI) * Ei;
@texture value rescaling
So I would create a specular map like usual but scale this down inside the shader to match the material's fresnel color ?