I've never seen any consistent difference in improvement from a change in any 1 incremental of the run.Perhaps if it is a fluke run where the short time is very smooth, the 330 is then very smooth, and so on, but I have never seen any indication that a good pass will somehow double an improvement.
I have heard alot of people claim multiplied improvements, but have never seen it. Doesn't make any sense that something done in the 60' can have any affect on how the bike performs on the back half, other than if it was just a good overall pass, and the smoothness of the pass allowed better other incrementals.