on efi extra forum this has been discussed recently and the conclussion is you want it lower than the calculated value to give better resolution.
the calculator gave mine as 7.7, but i had to drop it to 3.4 to get it running better.
really was a pain to get it idling right on the higher value.
i'm not saying it can't run on the higher values, but he accuracy of the values in the table will be less as the multiplier is much more.

if anything, i've found mine to be too high really as i can drop it by 30% or there abouts before i get close to max out to the 255 values in the table, this will make the values more accurate since the multiplier will be less.