P4314 Voucher Recost

I have read the white paper on Voucher Recost, and I have some questions.

We have situations where an invoice comes in for 100 receipt lines to match.  When they go to pick and choose (we have a lot of receipt volume) receipt lines to match, they only find 99 lines.  So they bring those back, add an expense line, and then place the voucher on hold.  After the receipt is done for the missing receipt line, they now want to be able to "rework" the voucher match for the invoice, and not lose their previously selected receipts.  Currently when you call up a Matched Voucher it wants to reverse the voucher match, and make