Hi @rcgillis !
Thank you for your concern.
Let me share something that can be useful:
As I was creating the dumb files to face the ‘filesize’ problem (as indicated in [OJS 3.3.0.3] Errors when trying to export issues), the number of Element ‘{http://pkp.sfu.ca}file’, attribute ‘filesize’: ‘’ is not a valid value of the atomic type ‘xs:int’ kept decreasing when I tried to export the article (two entries per dumb file created). When I finished creating all the dumb files for each article that had missing/renamed files, the export of the article started to work.
However, the number of Element ‘{http://pkp.sfu.ca}file’, attribute ‘filesize’: ‘’ is not a valid value of the atomic type ‘xs:int’ entries when exporting an issue kept always the same (as if the issue export process was based on a previous and outdated information about those missing files).
I don’t fully understand the issue export process, is it different than the article export process?
I hope I was clear… 
Thank you very much!!!
Kind regards,
Rui Pedro Silva