Why is part of my figure not rendering correctly? Some parts flash in and out.

That is Z-Fighting. It happens because some triangles overlap others (they are on the same plane). And the GPU does not know which one should be on top. In the case of VectorizerPath, make sure no part overlaps itself, by changing the StrokeThickness for example). Otherwise, you can use the Stroke Depth Offset material you find in the Assets/Vectorizer/Materials folder.

Will Vectorizer implement X Y Z in a future release?

I am happy to expand Vectorizer's features. Please contact me to discuss your suggestion.