""From what I know the shot doesn't last more than a second or so.""

That is the chart that I use. Per the chart, the pump cam can deliver fuel UP TO 50% or UP TO 80% throttle. At WOT, I am not sure how long the shot would last (in seconds pending on the pump cam).

Have you tested between the 40% secondary delay and the 60% secondary delay? If so, what have you noticed?
I have been going back and fourth between the two and I am still not sure which one to do my final tuning with. It may depend on the outside temps. Maybe using the 40% in the cooler temps and then using the 60% delay in the Summer months.