I was poking through the advanced parameters and noticed this textbox parameter:
control-files
Use this option to attach extra files to the newly uploaded filelists.
The command-line help just says the following, which seems more of a checkbox that textbox parameter…
--control-files = false
Use control files
I don’t suppose it would be something like “put a path here and that file will be uploaded as a separate file from the filelists”… ('cause that could be handy for making backups of the .sqlite databse, if one wanted to do such a thing)