eTransmitting a model from acc

I've been puzzling this out for a couple days and I'm stumped. If I wanted to make the process of downloading a prepping a model for eTransmit from BIM 360/ACC, how would I do that?

The process I'm trying to replicate:

1) Publish the target model and all linked models
2) Download the target model and all linked models to a local location
3) unzip the downloaded file from BIM 360/ACC
4) Open the target model and save as central file
5) Confirm all links are now relative
6) SWC / Close
7) eTransmit target model (and run cleanup tasks)
8) eTransmit creates a .zip folder

I assumed I would use the Project Backup task with the Transmit Model task, but I'm unable to get the linke models to download. 

Any hints would be appreciated.