I have called UAL three times and have been given three different answers to the same questions. The questions: As a 1K booking a M fare on an international flight can i get an instant upgrade if there are PN fares. I did search here and also found conflicting answers.

Agent 1: No, pn fares are not for international flights, no idea why you are seeing them - this answer I know is wrong.
Agent 2: Yes, as a 1K you can use GPU and it will clear if you book B,M fare
Agent 3: No, PN are only for GS flyers and 1K will not clear.

I would like to know: With an M fare, will:
A GPU clear if pn inventory is available?
Will an MPU (miles and money) clear with an M fare if PN is available?

Goal is get confirmed upgrade, I do knowledge of the pecking order on non-confirmed upgrades

Thanks

matt