I have two bikes with Easton carbon forks that are 100% carbon, even the dropouts, and they have no metal reinforcements. I have always tightened the qr skewers (Shimano and Campy internal cam type) to the same tension as I do for aluminum and steel dropouts and have never had any problems. After 33,000 miles on one bike and 29,000 on the other, if I was going to damage the dropouts I believe the problem would have shown up by now.