Certified PDF Validation?

Does OneSpan API have a validation feature to enforce a PDF has a particular certificate before creating a transaction? I noticed the "externally signed documents" feature is available but it does not appear to provide validation: https://docs.onespan.com/docs/using-externally-signed-documents

We are trying to solve a problem where we want end users to fill-out and upload a form template (via Salesforce/Apex SDK) for signature but the form must be certified.  It would be ideal if the api could do this validation for us.