You were just lucky to find that cashier. I don't think it's a good idea that people keep asking to override these coupons. No need to bring unnecessary attention when we're already getting a great deal from this promo.
Krogers in my area have Starbucks in them and they take these coupons as well.
BTW the generic T&S is pre-printed in the back of each coupon and it limits 1 offer per transaction.