On my old HP scanner, I was able to add documents to scan in progress, remove or add pages that are previewed before saving. I do not see this anywhere in the settings. When scanning from the feeder on the canon imageclass mf644cdw using the MF Scan Utility, when the are no more documents in the feeder, it immediately show the preview before saving but I am unable to add additional pages.
Usually when you scan from the feeder and it shows you the pages that were scanned, it has completed the process and has created the PDF file. To see what PDF options are available on your computer, I would suggest contacting support at 1-800-652-2666. Our agents would be happy to assist. For further assistance in the forum, please reply with the version of the Mac or Windows OS that is on your computer and we can proved additional assistance or some suggestions.