Need help extruding some strange shapes then flattening them

[JamesDraws]

hi everybody, relatively new to sketchup.
Spent the last few days youtubing myself to death on the program basics and some extensions.

Basically I want to do some sheet-metal work and want to figure out how to design some curved surfaces cut into individual strips that I can flatten, measure, (in sketchup) then cut and weld/bend with sheet metal.

so imagine for the sake of discussion that we are building a vent hood where we had a large rectangle that funnels down into a circle.(I'm actually building something more complex than this but I think the process hopefully will be the same)

I need a tool where I can set the dimensions of the rectangle, the diameter of the circle, and the distance between the two and have sketchup extrude the contour lines between them, then be able to un-roll that extrusion and figure out the dimensions of each facet when flattened.

I spent some time with the Curviloft extension and was able to do this quite simply, the problem came when it was time to unravel the drawing into flat strips. The model was made up of lots of rectangular pieces instead of linear strips and once I exploded the drawing I had a million triangles.

does anybody know of a better tool to accomplish what I'm trying to do?
Thanks in advance, James

[Box]

Have a look at Flattery.
https://sketchucation.com/pluginstore?pln=Flattery