How to default Delivery Priority on Sales Order Items from Ship To?

Is there a way to pull the Delivery Priority from the Ship To partner when creating sales order items rather than pulling from the Sold To partner? I've checked all of my documentation -- including OSS notes; searches on SDN, IT Toolbox, and internet. This doesn't appear to be configurable. Can someone confirm that or tell me how to configure? If not configurable, what is the recommended user exit?

Thanks!