If the arrow is properly spined for the bow so that the danger of it shattering from over bending is negated, then the danger of damage is the effect of stored energy going back into the bow upon release.. That is after all what a dryfire is... there is no arrow to absorb the energy produced by the bow..
An arrow which is within the 5 grains per pound ie... a 350 grain arrow at 70lbs and 32" of draw is by theory safe to shoot. But in practical experience there is a lot of energy that is lost back into the bow.. this is the very reason that a heavier arrow is quieter and smoother than a light arrow fired from the same bow..
So... I guess the answer to your question is... one is ok under the stated warranty and the other isn't... which does more damage to the bow.. probably not a big difference in the real world..
Mike "Javi" Cooper