When people talk about the main system coming in sooner or later I have always assumed they were referring to rpms. When I said time based I was referring to rpm as time. I should have just said rpm. I get that the throttle position changes where the boosters start flowing at different loads. But you have to have some sort of reference to make a comparison. I guess I could use throttle percent opening but I would have to rig up a throttle position potentiometer that produces a 0 to 5 volt signal and convert that to percent of opening. Really I think the results would be the same as using rpm. Wouldn't they? I don't know.
