"where the international segments had confirmable PZ upgrade inventory available." Here lies the difference, almost never finding PZ for my flights it doesn't make sense. But given your situation I can sort of see it. I still ending up eating literally hundreds of PPs at the end of the year so hard to justify trying to "save" them in almost any scenario. I realize others find ways to use them but FT is filled with pax like me that find them rather worthless. As I stated above I'll be using them for other things now going forward such as status upgrades for family.