The support team suggested we request a feature request for a gadget here. We had an issue where a client had site visitors vote for a school district award. Apparently there is some unknown threshold where the number of form submissions is large enough that it cannot be exported before the DXC environment times out. I've included the response below.

Hi Kenny,

If the deployment is in DXC the execution timeout cannot be modified. Timeout is enforced by Azure load balancers and by default is 4 minutes. This cannot be solved in web context.
The EPiServer.Forms.UI.DataExportingController does this:

- Prepare the Export
       o Get all submissions
       o Summon the Exporter
       o Exporter converts submissions to binary data
       o Write to (in UTF-8) bytes
       o Save to temp file
       o Return temp file to clientside via a JSON object
- Export
       o Return a FileStream to clientside

The only recommendations in this context would be to possibly disassemble our DataExportingController write it in a schedule job or console.app (so it does not have execution timeout) to send the export file via email.
We also recommend adding a feature request in our forums for a gadget if needed.