I tried without success to find the actual rules stated somewhere clearly in recent thread. But following the links above I saw something I missed in the T&C
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Number of Upgrades: The number of 500-Mile Upgrades required to upgrade must equal or exceed the total miles flown between your origin and destination cities.
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The general info on FT is that it is the number of miles between origin and destination that determine the number of certs, provided all segments clear before hand. However the wording says "total miles
flown" which is not at all the same thing.
So I'm still confused as to the actual rules.