Presently a DataDump for Excel does not persist until the testcase is finished.
Ideally it should persist to disk once the teststep is finished. Currently you're prevented from immediately using the file generated in a subsequent API call within that testcase. In my case I had to abstract the data generation into a separate disabled testcase and call an execute testcase teststep to generate my data and then use that accordingly.
It was an unnecessary complication for me.
Thanks in advance.
Ken.