<add name="Access-Control-Allow-Origin" value="*" />
Thank you for contacting Syncfusion support.
We have validated your query in uploader component. We have already considered this was an improvement in file upload. So, the implementation changes for this improvement in the uploader component will be included in Volume 4 2018 release which is expected to be rolled out in the mid of this month (December, 2018).We appreciate your patience until then