The difference between DZ Extended Tax Recalculation and DZ Tax Recalculation is that:
DZ Extended Tax Recalculation requires that the document has a Batch ID, DZ Tax Recalculation does not.
DZ Extended Tax Recalculation saves the document as part of the recalculation process, DZ Tax Recalculation does not.
DZ Extended Tax Recalculation generates a report of the changes made to the document, DZ Tax Recalculation does not.