Yes, but that is the size of the mediumbox; not of the trim box.
I also implemented the script; it helps a little bit but only to the page that is visible, not the whole document and I can't leave it open for other pages to show the box sizes. I have to klick on ok before I can move to another page etc.
I was not sure if you really meant trimbox or mediabox, as you mentioned moving the zero point in say InDesign, and in InDesign the the visible document page could be the mediabox if no bleed or slug is added, or it could be the trimbox if there was bleed or slug.
Yes, the script has limitations, it was originally intended for Acrobat Reader users that don’t have all of the prepress tools found in Acrobat Pro.
I do have a solution for you that I hope you like:

Using the print production tools > preflight > single check > options > create check it is possible to report on all of the trimbox info from multiple pages in a single floating panel.