Terms code changes and Discounts

We are changing a terms code of a vendor.  Going from no discount term to a discount term.  Edited the address book terms code and manually keyed vouchers pull the new code correctly and compute the discount.

Matched vouchers assign the terms code attached to the receipt.  Is there a way to change the terms code on the open receipts?  These all have the terms code assigned at the time they were created.  We can override when matching, but there of 1,000+ open receipt lines and the terms can be easily overlooked during the match process.

Followup on that is editing the terms on existing vouchers that are posted.  Speed release allows terms code change, but a discount does appear to get computed with the change.