I wonder if this could be used in conjunction with this feature
…which is intended for use online but it could easily be expanded to use in physical locations as well.
For your example, after the initial transaction at the restaurant, you could hypothetically tap on the merchant and select a virtual card from a list (or create a new one) to use for all future transactions at that merchant. You can thereby freeze/block that particular merchant. Any attempts to use the details of the actual card will be diverted to the virtual one and declined. Might be less work in the long run.
Would that be an acceptable alternative?