LTM4671 OUT1 & 2 (5A output ch) efficiency

We are considering using OUT1ch with 12V input 0.8V 2A output.
With efficiency near the data sheet (12V input 1V 2A output)
I looked at the efficiency calculation result in LTpowerCAD.

The two were quite different.
Q1: Do I understand that the data sheet is more correct?

Q2: If Q1 is YES
Since LTpowerCAD cannot rely on the conditions of 12V input 0.8V 2A output.
Is it correct to understand that it is inferred from the close conditions of the data sheet?

[edited by: UBOTI at 1:38 AM (GMT -4) on 16 Sep 2021]