Default filename using the DataDownloadservice is : http://fmeserver/fmedatadownload/FME_2D764B0C_1515155526785_73956.zip
Create an FME_SERVER_PARAMETER on FME Desktop like : FME_SERVER_ZIPFILENAME that can override this name if not empty. Then you can easily create a complex output-file based on both published parameters and attributes created during the workspace. For instance in a workspace you have:
PUBLISHED PARAMETER
Startfilename = "3Dmodels"
attribute created within the workspace:
timestamp = "20180101"
FME_SERVER_ZIPFILENAME = "Startfilename + _ + timestamp"
Will give the filename:
http://fmeserver/fmedatadownload/3Dmodels_20180101.zip
and automatically this will be the downloadlink instead of the default:
http://fmeserver/fmedatadownload/FME_2D764B0C_1515155526785_73956.zip