For the next prerelease we add a new DynaPDF function for both FileMaker and Xojo to show differences in two PDF pages.
This is a new function written to annotate a page in a PDF with highlight annotations if two blocks in a the pages have different image. This works well here and shows differences in various PDFs. We include a check to make sure that lines moved up or down on the PDF page don't cause to be highlighted.
Please try soon in next prerelease. You'll need a DynaPDF Pro license as this is based on the render feature.