slotty,
That is what Jaeger advocates during the pull down phase. Personally, I believe the pull down phase is more for re-establishing the release point. Jaeger believes that the velocity gains occur when continuing to attempt to exercise max effort during the pull down. Personally, I believe the gains come from the throws at max distance and there may or may not be some transfer to the "normal" throwing motion made by continuing to throw hard while pulling down.
The ASMI long toss study, although flawed in it's conclusions due to improper measuring of the velocities during max distance long toss, pretty clearly showed that the max loads and therefore the max training occurred during max distance throwing.
I don't have any problem with max effort coming in as that probably helps with re-establishing the release point but I don't think it makes much if any difference with the velocity and that's the part I'd be most likely to cut short if the arm was starting to get fatigued.