Audit trail for specific fields on a document

We would like to use Adobe Sign to collect missing information on a mostly pre-filled log (see attached example), but it is important to be able to tell who filled in the fields that were initially missing/blank after the form has been completed/signed.

When you open up the signed/completed document in Adobe, it is not clear which fields were pre-filled in the form and which were filled in by the person who signed it. The audit report from Adobe Sign only includes details about when the document was emailed to someone and then when it was signed/completed, but we need an easy way to be able to tell what was prefilled and what was completed once it was sent for review/signature. Does anyone know if this is possible at all?

Note: We are not just able to assume which fields were filled in using Adobe Sign based on the differences in the text font/sizes - this is for clinical research so we must have an official, Part 11-compliant way to show where the source for this information came from.