Hello,
I've been using Indesign for over 20 years and I often come across the following problem: you're working on a large catalogue, you export it as a PDF and after proofreading, a page needs to be corrected. You apply the correction and export the whole catalogue again, overwriting the previous one, or (another method) you export just the corrected page and import it into the PDF using Acrobat tools.

It might be interesting to be able to tell Indesign to export only the corrected page and to integrate it directly into the existing PDF in order to save time either exporting or manipulating the page with Acrobat.

I hope my explanation is clear enough.
Thx!