This time I tried  'mr_looper4e_edit.py' on a cylinder prop. First try I got this.

Created plane
Callback started
Starting callback
Callback is running
RUN SCRIPT 0.0
END SCRIPT 0.0
[more of the same]

I have been typing the "1" rather than spinning the dial. If I type the number in nothing happens. I decided to try dialling it in. That worked to some degree, but it was not possible to get exactly 1.0 on the dial. I set the min and max for the dial, then turned on Use Limits. I got this.

Created plane
Callback started
Starting callback
Callback is running
RUN SCRIPT 0.0
END SCRIPT 0.0
Callback is running
RUN SCRIPT 0.0
END SCRIPT 0.0
Callback is running
RUN SCRIPT 0.0
END SCRIPT 0.0
Callback is running
RUN SCRIPT 1.0
Starting loop generation
Making loop
Getting actors
cyl_1
Found vertices
Convex hull generated
Perimeter markers placed
Ring vertices placed
Verts, polys, sets created
UV mapping applied
New Geometry() instantiated

In spite of the encouraging message "New Geometry() instantiated", I see no new props in the document window, or in the dropdown Props list, and MR Looper is still just a plain square.