What does the KampData TaxEngine use as the Default Tax Schedule?

A KampData TaxEngine document is created using Document method.
The new document's Site ID is set to the Site ID specified in the Document Defaults section of the Sales Order Processing Setup window.
Since no Shipping Method has been assigned at this point, the Shipping Type defaults to Pickup. As a result, the new document's initial Tax Schedule ID is the Tax Schedule ID specified in the Site Maintenance window for the above mentioned Site ID.
When a Customer ID is assigned to the document by setting the DocCustomerID property, the customer's Ship To Address ID is automatically used.
If the Shipping Method specified in the Customer Address Maintenance window is not blank, then the document's Shipping Method is updated with this value.
Based on the Tax Location resulting from this Shipping Method, the document's Tax Schedule ID will be updated as appropriate to the Tax Schedule ID specifed in either the Site Maintenance window or the Customer Address Maintenance window.