There is a defect in the script if the Frustum is "upside down."

In other words, if the selected "Base" circle of the Frustum is of smaller radius that the selected "Top" circle.

I think this can be corrected by exchanging the length values of the Top and Bottom in the code...

- Brian

(The script does not unwrap cylinders.)

The Unwrap is called a "Net" by mathematicians.

Also, the script is leaving behind copies of the circles and slantseam line.