I say go back to 500 milers and call it a day.
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Another option is to have a more complex scheme of combining status and fare class for upgrades based on some formula. E.g., a 1P in Y could never trump a 1K in B, but might trump a 1K in L.
I agree and I agree. The first will never be resumed.
The second point had been mentioned previously, the poster even providing a stylized pyramid. But hell will freeze over before UA IT will demonstrate the capability to do something like this.