not only a decrease in ASDA, but also in TORA?
Philosophically, ASDA is critical because the aircraft is on the ground throughout ASDR. However, the last part of TORR is airborne (by definition) so that may permit a lesser concern in regard to declared TORA.
Clearly, were the decrement to be significant, TORA would need to be revisited but, for the typical short distances involved, the aircraft still is going to be airborne for that remaining TORA delta.