Hi Scottpipia,
The Checkout UI Extensions SDK does not directly provide access to the customer’s saved shipping address. This is a part of Shopify’s design to ensure customer data privacy and security.
As a workaround, you can use the Storefront API or Admin API to fetch the customer’s default shipping address (as well as other details such as name, email, etc).
Please remember, due to privacy concerns, you’ll need the customer’s access token to fetch this information. Hope this helps!