Steamaway question

[Johnny Cuervo]

Hello all, a steamaway claims a 2x4 flue pan to increase 20 GPH. My question is
do they compare this to a 2x4 without a pre heater? How much of this gain is from pre heating, and how much is steamaway evaporation?

Did anyone pre heat, then add a steamaway? If so what was the increase?

Thanks