The help on the BookDtl.BookType field:
Indicates order entry activity for which this record was created. “New” - added new order line item. “Chg” - change to order line item that affected bookings. “Rvl” – revalued order line item. “Del” - deleted sales order line items. “Void” - voided line items. Note: When an item is voided the “outstanding” qty and value are used.
So “Void” Types only look at outstanding balances.
That is what I would like the Change Option to do.