Dunno. I know more local people who have consistently made more power on E-85 than race fuel.
When E-98 is brought into the argument, there is no comparable race fuel, besides Methanol.
I've got 2 zetec Foci on E-85 and I've no complaints. I can't imagine the duratec is that different, or would take much to tune for the fuel. The zetec is very easy IMO.
And that is all I'll say. Far too many arguments start and not enough people have first hand experience.