When importing draft orders with EZ Importer, if Shopify returns the "Base Change merchant of record on this order to do the following: create an order with zero value" error, it indicates the customer is from a managed market.  Shopify automatically selects the merchant of record based on the customer's shipping address or the market configuration in your Shopify store. Shopify doesn't allow apps to manage or configure these settings.

Shopify recommends reviewing the managed markets documentation to understand its limitations. For further details, you can read this Shopify forum post.