Is there any way to create separate files for the output of a mass mail merge?
Looks like this question has just been discussed, please have a look https://forum.aspose.com/t/128519
The separate files will be used for archiving. Can I also generate a consolidated file for submitting to a print shop at the same time?
You can do this either by running a single mail merge operation for all records in your data source. The document content will be repeated and merged for each record and it will all happen inside one document.
Alternatively, you can combine documents using Sections and Section as explained here https://docs.aspose.com/words/net/insert-and-append-documents/