Quote - Hint.

The Diffuse node formula (roughly) is:

Diffuse_Color * Diffuse_Value * Cosine(alpha) * LightColor * LightIntensity

That is only for one light. When there are multiple lights, that is evaluated for each light and these are all added together.

Which is a bit different to:
diffout = clr * I

Rethinking everything. I tend to look at details and fail to abstract the core equations. Something wrong with me, there.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

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