Option to automatically add a product to a deal with workflows

Hi,

Current hubspot customer with a growing e-commerce business that did turned over 1million dollars in less than 10 months from launch. We have a 2 shopify stores. When an order comes in, it goes into the production cycle as we make to order.
Current use case:

1) Shopify integration creates deal with deal info, contact info and line item info and associated them all into the sales pipeline

2) We have a workflow that then creates a new deal into the production pipeline. Reason for creating a new deal: the shopify integration has control over the deal and whenever it syncs, it pulls the deal back. Having this workflow is the only workaround I can find. However, I can only create a deal and associate the contact, not the line item.

It would be useful to associated the line items in new deals.

Thanks