Looking to buy economy on emirates from JFK -> DXB -> BKK and then use Korean Air Skypass miles to upgrade. I've called both airlines, Chase and Amex and no one seems to know the other's side of the equation.

Has anyone transferred Chase points to Korean Air Skypass and used them to upgrade an Emirates flight?

Emirates rep says only Skywards miles can be used for upgrade.
Korean rep says Skypass miles can only be used for purchase (not upgrade).
Chase & Amex say 'call the airline'.