or the Story of a Rewrite.
The Single Light Lambert node in our free collection of plugins was never designed to replace surface shading in LightWave, but to allow the control of other nodes depending on the lighting by one (or more lights).
An simple example would be assigning two different images two a globe depending on wether it is lit by the sun or not.
Given the (much needed) changes to lighting and shading in LightWave 2018, we initially used a function marked as "legacy" to get the node to work.
Granted, it did work. But not when writing to a custom AOV - at least not in VPR - and it produced some odd results.