If you add a default content document to a document set content type and create a new document set from that content type the default content will have it's title field set to the filename including extension. This contradicts the default behavior where templates uploaded to the new-menu and default OOB templates defaults to an empty Title field.
Is there no way to specify the tile field for default content in document set content types or to set it as empty?
This will for example override the ability for SharePoint Search to extract title from within the document for use in search results. Instead it will show the file name including extension.