Combining lights/lighting (masks) in a material

I recently implemented this iridescence-shader: Building an Iridescence Shader in UE4

Within is the possibility to use a light-vector. Fine, but only one… :frowning: I can certainly rerun the maths for the lighting-stuff across multiple vectors (lights), but how/when might I combine them, average them I guess?

The lighting math looks like the strength of influence on the highlights in the material, a mask. So I would hope this is a general-enough question someone might be able to point me in the right direction. Do I just Max between all the results?

If it’s too specific just tell me, thanks.

ref, top-righthand corner for the lighting info: