I feel very strongly that your scenarios are not only highly optimistic but that they also pretend the climate crisis isn't real.
You assume that after 20 years, the contracts will just be renewed. Kinder Morgan, in the original toll methodology, clearly said they wouldn't go beyond a 20-year period because there was simply too much risk.
Would you agree that the world will be in a very dire situation if this pipeline continues to pump out bitumen at full volume for the next 40 years?