Being able to send proofs using the real data passed through via the workflow would eliminate a pain point in Adobe Campaign. There is no real way to test personalisation fields using temporary file data without running the email as an actual send.
I believe you can create audience using file data and test the personalization using profile substitution without an actual send. You can try and see if that works.
You need to Create “Live” Profiles to Spoof User Data or you can also use ACS New Profile Substitution Functionality