Using Kami Offline

We are attempting to use Kami with our practical nursing students. We are using google classroom to assign topics and chromebooks for the students to annotate on pdfs we have prepared. The issue we are having is that when the students go to a clinical site (hospital, etc.) they do not have online access. Thus we are “printing” the pdfs to save their annotations while they are offline. Unfortunately, they cannot change or remove annotations when they “save” the file this way. We have had several students leave kami open over 2 or 3 days to keep their annotations editable, however, they will sometimes lose their edits (via loss of power, unexplained reasons, etc.) Can anyone suggest a way to help us figure out a better method for working offline, saving the documents so they are still editable, or being able to delete old comments after export? Any suggestions would be greatly appreciated.
Thank you,