I wonder how it works in surrendering your Upgrades earlier. I have done this before..but I wonder if you surrender a now VALID confirmed upgrade in advance of a flight... would they take it and accept it for a flight where it would not be valid on? (ie expired).
Either way.. I traded a Systemwide for 4 500 miles in the Red Carpet club.. the CSR did not seem to mind me giving them instead of the systemwide even though it was a confirmed upgrade..
Neat.