Thank you Rick, I found where to make this entry. It is Dependent Student Info Worksheet Part VIII, line 2h where I had to manually enter the Adjusted Qualified Expenses applied. Otherwise, it populates as zero thinking the entire Qualified Expense was covered by AOC despite me opting out of AOC.

By doing so the taxable amount of the 529 gain was lowered proportionally to the amount of distribution that was qualified expenses. In this instance 13% of the gain was reduced while 87% remain taxable.

Is this what you would expect?

Thank you. Every dollar helps!