Well, I have the video and cant do it as you said. However, i redefined variables
cropwidth = 0
cropheight = 0
cropleft = 0
croptop = 0
As they say in my country, its to kill a fly with a cannon, but for now I serve. Thanks Robert.
EDIT: Without redefined variables, with this code I got what I wanted. Simply, firs resize and after upsize ^^
Code:
Spline36Resize(720,540)
AssumetFF()
SimpleSlugUpscale(size="1080pana", parout=1.0)