LSCS Fan out works but nothing for LSDS.

System

LS 7.1
LSCS and LSDS is running together on each server in the farm.

We have a CSURLExternalTask that uses StartDeployment.trigger to overide the manifest and deploy to LSCS. Nothing in our task does the LSDS deployment and it obviously is not happening. I am kind of at a loss on where to look next. The Publish LiveSite Content workflow has a Deploy Files cgi task, but where is the source for that so I can explore it? Better yet which pdf should I be pouring over to glean this info from?

Thanks