better actual acceleration lift changes with acceleration=more lift with given unit time/distance-- the wings are working at a lower pressure altitude because the temp is only 'assumed' for the engines, but the engineers don't take that benefit in account and it gives a margin---
And better stopping [before V1]with reverse becasue you get full rated RT [that's why it unofficial because in part 25 dry RT doesn't exist,]also spoilers and retardation devices are better in the denser air
SNS3Guppy do you see why I said "you gotta wash'em out in ground school"?
