Rather than the Page number technique, I use Data Merge; but i seldom print more than 500 in a lot.
The 1000 page document cannot be as low as 3.5mb, IMO.
With the Creo, you might consider saving the common master elements as a Print Master in the RIP, and print only the page numbers; using the RIP to combine in the Master.
700 digital press with creo rip software
Can you submit the PDF to the RIP instead of printing postscript from either app?
I'm going to compare apples to oranges here...
I did 250 sheets for 1000 tickets this am.
See the graphic, (in Explorer's Preview) It added far more data in the RIP than I should have allowed.
While the InDesign file was only 1.4mb, after merging to 250 pages and spooling it weighed in at the RIP at 1.5gb. (Fiery RIP)
I had to get up and go do some other work while it processed.
I think there is something wrong with a 1001 page pdf at 1.8mb as you're showing.
If it is indeed that small, you could host it or email somewhere; we could verify if it works or crashes on another system.
PM me as needed to send the pdf
You have what seems to be a bitmap image in your background. It is possible the OP is using a solid colour or vector shapes for the background with the page numbers. In which case, if there were no bitmap images, effects etc, his filesize should be achievable.
I think the issue might be sending so many pages to the printer at once as it needs to process one at a time. Could try sending batches of 100 and see if it makes any difference? This can be done in Acrobat by selecting 'pages 1-100'.