CNTCT_SEQ_NUM in Billing doesn't flow to AR?

Hello,

At the University of Colorado (9.2 Image 37) we are exploring the idea using the delivered emailing feature for AR Dunning & Statements. As our Items come from Billing, we need the statements and letters to use the contact entered on the bill.

It seems the system isn't designed to do this. CNTCT_SEQ_NUM is not on PS_PENDING_ITEM. If a contact is checked as the Primary Bill To under the contact setup, it will default in on the AR Workbench for all items for a given customer. But we have customers with multiple addresses, and different contacts for each customer address, so the Primary Bill To won't work for us.