Do you mean for craft damage? I don't know about that, but for weapon damage there's the "TFTD damage rules" advanced option that does exactly what you want.
He meant damage in general (all types).
The "TFTD damage rule" does
NOT do exactly what he wants. It changes the damage range, but it is still a "single roll", not "double roll"... as illustrated by the code snippets I have posted earlier.