Perhaps to make the submissions in this list easier to distinguish from one another the ID could be included?

Perhaps to make the submissions in this list easier to distinguish from one another the ID could be included?

You could add the ID to the subject line. What are you trying to do though? Are you trying to hide the form when you a user has already submitted?
Adding the ID to the subject line could be an option. Though if you want to keep your subject lines clean then perhaps not. If you set up two email actions, one to send a notification to admins and the other to send the user a confirmation and both with different subject lines, what subject line would be shown in that dropdown in that case?