Allow specific Shopify Cart Attributes to be mapped to ShipStation's CustomFields. This would need to be based on the key of the Shopify Cart Attribute. For instance, the Cart Attribute with the key of "date" might be mapped to "CustomField1".
Cart attributes are Shopify's primary extensibility point for individual orders, allowing app, theme, and shop developers to add custom properties to an order:
https://help.shopify.com/themes/customization/cart/get-more-information-with-cart-attributes
CustomFields (e.g., CustomField1) are the analogous concept in ShipStation:
https://help.shipstation.com/hc/en-us/articles/205928478-ShipStation-Custom-Store-Development-Guide#...
ShipStation currently imports Shopify Cart Attributes as part of the [Notes From Buyer] field. ShipStation, however, does not allow Shopify Cart Attributes to be mapped to CustomFields, where they can easily be assessed by Automation Rules, displayed as part of the orders grid, or independently included on the Packing Slip Template.
By allowing these two related concepts to be mapped to one another, store owners and developers would have tremendous flexibility to integrate extensions to Shopify into the ShipStation workflow.
Note: A common use case for Cart Attributes is the ability to collect a requested delivery date, which is of particular relevance to shipping and order fulfillment:
https://help.shopify.com/themes/customization/cart/add-date-picker-for-delivery-dates