I have a Loc IV and want to extend the length with a payload bay of about 11 inches which is a stock item from "Melissa". That increased my margin to just over 4 which is of course overstable where as the stock Loc IV has a margin of about 2.63. These numbers come from Rocksim. My question: how large can the value for the margin be and the rocket still be considered stable enough to fly? In other words, can the margin be too great or can a rocket be too overstable?