A similar setting already exists in PayFabric Batch Charge security settings.
It would be helpful if not required to have a setting for the Square Batch Charge to have a setting that allows a user to "Charge Card Of Prior Authorization" which when set to True the Square Batch Charge function would look at the current sales document it is processing and if there is already an authorized card on the document, use that same card number to charge the full total of the document.
Currently, Square Batch Charge only looks for the default card/wallet on the account or if there is no default set then it randomly picks a card on the account to charge. Both the default card and the randomly chosen card may not be the card that was authorized on the sales document resulting in the customer being charged on a different card than they authorized for the sale.