If I am reading things right (a question in its own right), the time lag Tracy is talking about is the response time an injector to a given pulse.  This affects linearity of the fuel delivered vs pulse width relationship.  The longer the pulse width, the smaller the effect of the speed of injector response.  The recordings of pulses I’ve made indicate that the primary and secondary injector pulses arrive at the same time.

Always willing to be educated…

Steve Boese