There is zero mathematical difference between the old and new methods, assuming bb did his sums right. (That's bordering on heresy!). But adding in the other effects might be a bit awkward.

The suggestion I made in the other thread about adding the (attenuated) Diffuse and Specular after separate gamma correction is clearly wrong, as that would be a non-linear addition.

I need more bananas... oh, and chocolate.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)