Ok all is normal ! I made a false confusing process with folders ! :)

About your script.
It's not like for an image say : 1024 * 716 pixel so 36.12 x 25.56 cm

Draw a rectangle 32.12 x 25.56 cm

With this rectangle and the Edit Frame give it any homothetic measures wanted! Make any adjustments...

Then Menu View / Image / Add in this new rectangle with 2 clicks:)

But maybe I I didn't understand everything of your pluging!