Answer: The scaling factor is not the value to scale up the artwork, that field is intended to enter the scaling down factor of artwork to bypass the limit of 200inches in PDF technology.
In this case, since the final wanted dimension is 192"x72" and the artwork is 96"x36" then the scaling factor must be set as 96/192 = 0.5 = 50%
The formula is: art size / final size
All the dimensions set in the script as the bleed size, the white space size, grommets spacing, etc. must be entered as wanted on the final size file (192 x 72).
The script will automatically adjust them considering the scaling factor.
For example, if the needed bleed on the final art is 1 inch but the uploaded art is scaled down at 50% then the script will add 0.5 inch bleed. When the file will be then scaled up by 200% on production then also the bleed will be doubled.