You can create a subfolder generation and file renaming scheme that contains a Job Code, and one that does not, and apply the scheme as necessary to the files you wish to download.
You can even take your existing subfolder generation and file renaming presets, modify them to remove the Job Code and extra hyphens, and save them with a new name as new presets.
You then simply select the correct saved presets before you download.
It’s much, much simpler than having a Null Job Code, which will confuse almost every user apart from yourself.