OPEN DES,
I realize that, as you say, the 'minimum fuel flight' in your post #8 is 'academic'.
But, considering that the reduction in tripfuel obtained by descending at green dot instead of some higher speed is due to lengthening the descent distance, i.e. starting the descent earlier, I'm wondering if the FMC allows you to calculate the top-of-descent point for a green dot descent?