Nope, anything between 5 and 7 degrees is good. Originally I was going for the “book” amount of 5.3 degrees, but many people seem to find that a little more is better. I set it up for 25mm offset instead of 22. There is some adjustability in the suspension.
In a car that weighs 1100lbs there is no need to consider the extra weight and power drain of power steering.