I’m afraid codification logic is not supported at this time. The way gravity forms implements this creates a challenge for updating files asynchronously and still trying to find a solution.
If you have any dev experience and can help please feel free to post a commit to the plugins github page.
one other question > do I need to manually delete the CHUNKING subfolders that get created for each upload ? or is there a setting I need to adjust to do this for me ?