The way I throw, which may or may not be "correct", the first 90 degrees of upper body rotation is passive. I'm not turning my shoulders, I'm allowing my weight shift to aid in snapping my upper body back to "neutral" after twisting it away from the target.
With this in mind, that motion takes about the same amount of time regardless of how far I reach back. SO, if I reach back further, the disc will have moved a longer distance in the same amount of time, which equals more speed at the hit. More speed at the hit equates to more distance, as long as you're not going so fast as to mess up your timing, and still hit it.
Anode | Comet | Axis |Vector | PPD | SPD | CPD