How would I extract the Isocurves from this polysurface

So I created this pyramid shape from an extrusion command and as you can see it is a polysurface broken up into multiple faces. I tried to cap the bottom but it said it was not planar. I want to get the horizontal direction isocurves that go AROUND the shape instead of along the shapes naked edges, however whenever I try to use the extract isocurve command, it only lets me extract a small piece of the “band” that goes around the shape. What would be the best way to extract those Isocurves going around the entire shape as curves? (I turned on show naked edges so you can see what I mean by the shape being divided into individual slices.)

there is no way to do that unfortunately, you can use the option all for each surface if that helps you speeding it up, other than that you would have to extract them for each surface separately.

but why are these edges open anyway? did you not use the command join or is that intended to stay open for some reason still?

Hi Gabriel - it could be there is a better way to go about this - please post a Rhino file with the surfaces and the input curves.