Based on the additional information afforded by the above. There is a code modification that I am staging to github to address this issue such that DPU will still update prices of product with attributes even for product that are out-of-stock.

This change does not require modification of the template files. Further, it will identify the price associated based on the quantity identified by the ZC function zen_get_buy_now_qty for product that are out-of-stock and for quantity entered as zero or negative.