The old mod/assignment had a setting to allow users to upload draft files and then "finalize" or submit the file for marking when finished.
The plagiarism plugins checked if "var4" existed in the form and added a setting to control whether to send each draft file to the plagiarism plugin or to only send on the finalized event - it used a different event trigger for this "assessable_files_done"

We need to port this functionality to the new mod/assign - checking to see if the drafts feature is enabled and enable/disable a drop list to allow configuration of when to send the file. and then we need to be able to check to see if the user has submitted a final time or if the file is still in draft form before sending to the plugin (it doesn't need to happen using a different event type - just whatever looks most effficient.)