You very well can make this a reality. In a List Workflow the Item Property "Document ID" refers to the perma link to a given Document or DocumentSet in this case. 

So right off the bat you have the URL. However, the way in which you can leverage that will require a bit more of an understanding of what the circumstances of your environment are. 

If you're just pushing that URL into your "working area" list, and a NEW list item is being generated with this URL as some of its metadata, then I recommend just creating a Workflow on the Document Library that Automatically Starts when New Items are Created:

However if you need this URL to be pushed to a specific item elsewhere, then you'll need to either send some sort of useful ID that'll get saved to the DocumentSet's metadata when it's created (So the workflow that runs against it will know where that URL needs to go to), or make the Workflow (in the Document Library) in such a way that when you call it remotely, you can pass along a starting variable which tells it which item in which list to target. 

Let me know if this solves your problem or if you need further help!

@MegaJerk Thank you for your response. I am going to try this suggestion "However if you need this URL to be pushed to a specific item elsewhere, then you'll need to either send some sort of useful ID that'll get saved to the DocumentSet's metadata when it's created (So the workflow that runs against it will know where that URL needs to go to)"  because I have the ID number from the working list being sent when originally creating the document set in the working location. When the same document set is sent to the final respository it takes the ID number from the list with it.

I'll let you know how it goes.