Regarding running a tab: When I use Apple Pay at a gas pump, it first creates a temporary charge for more than I'm likely to spend. When I'm done pumping, it c

Regarding running a tab: When I use Apple Pay at a gas pump, it first creates a temporary charge for more than I'm likely to spend. When I'm done pumping, it charges the actual amount and removes the reservation. I wonder if a bar tab could eventually work like that, where you temporarily hold $50 or whatever and then reconcile it when I close my tab. As a bonus, you'd never have someone forget and leave there credit card there again.