Should a long-term debt be returned on the due date for the amount previously borrowed or its current value today?

Some scholars rule that it gets paid with the same amount promised in the past regardless of the difference in value.
Some scholars rule that it gets paid with the same amount unless there is a drastic drop in value below 1/3 of the original value of the promised delayed amount.
If it drops below 1/3 in value, the two parties have to share the loss together to a certain extent and settle to a fair compensation amount to make up the difference.

We personally lean toward the second opinion because it is closer to fairness in our view.