How Does Adding Custom Line Items Via the Advanced Setting Work in the Shopify-NetSuite Integration App?

Question:

How does adding custom line items via the Advanced Setting work in the Shopify-NetSuite Integration App?

Answer:

When a user selects a "Noninventory Item" to add as a line item of an order, the Integration App holds "Item Name" information of the selected item and uses it as an SKU to add a custom line item to every order before executing the mapping process (ex: Dynamic mapping).  If a custom line item is added via the Integration App, it only contains information that is provided by the Integration App and not the properties that are expected by the Shopify line items (like variants).