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when you input a curve and plug it into Divide Surface, that (Planar) curve gets automagically transformed into an Untrimmed Surface
generally speaking, for a Planar Curve, its corresponding Untrimmed Surface is usually its bounding rectangle
so what Divide Surface tries to do is the following:
and when subdivision points will fall on the red area they will be output as Nulls
difficult to say without code, but I would place an Untrim component here, in such a way a final Surface from Points is generated, and then trim that surface smaller using the extruded initial curve as cutter:
it’s just a screenshot, but I don’t really understand the function of these components 
A) looks like sorting Lists of 1 single item, so input = output
B) looks like picking the first item from Lists of 1 single item, so input = output
