You know Better Visibility - Transparency would be for UA to show, at least for the passenger, their information on any/all upgrade lists.

Read back from upgrade list(s) - 1K booked B-fare and therefore I know I'm in the system properly - That's better visibility!

I know on my original booking with an originating connection that was M-class and the upgradeable flight was B-class. The Mileage Co-pay was trying to charge me $350 which is wrong for a B-fare ticket (i.e. M-class originating flight did not have upgradeable cabin).

Not really knowing how the system is reading your information is the definition of Opaque.

Some agents will go the extra mile to ensure your information is correct in the system and some won't.

So United - give the user better insight and you'll get less Customer Service calls and lower comp $ from disgruntled passengers.

End of rant.