Can code in the QP_CUSTOM package reliable reference the order in the database?

I need to do a workaround for the Bug 6418373 - PROMOTIONAL GOODS OFFER DISCOUNTS ARE NOT APPLYING. I need to be able to compare the lines on the order to determine the discount in the QP_CUSTOM package.

In Oracle Advanced Pricing White Papers (Doc ID 136687.1), there is a White Paper;

Do Not Customize, Extend! (Using the Get_Custom_Price API)

It has a code examples that sums the ordered_quantity in oe_order_lines_all table. Is this reliable? From my testing, I am finding that the QP_CUSTOM package is called before the commit.

When first entering the lines in an order, it is possible that the lines have not been commited to the database yet. When navigating out of the lines block, it will call the package QP_CUSTOM and then commit. So the state of the lines table would not be commited and out of date when using them in QP_CUSTOM?