In my experience, if you get up and walk to the reception counter and tell them you’d like to settle your check, they’ll let you. I’ve never once been told “you need to go back and wait,” because at that point it’s false imprisonment. They can’t keep you. Pay at the counter and leave no tip. Just, don’t return (at least, for a while, let them forget about you).

If it’s a restaurant in your neighbourhood, obviously give them a bit more time because you’re going to want to go back. If you’re traveling, or if you never want to eat there again, by all means, stiff them on the tip if you feel it’s warranted. You have no stake in it.

I love pay by QR code (the way I see it done, after you get your meal they’ll ask if there’ll be anything else, you say no, they bring your receipt while you’re still eating, you just scan it, pay on your phone, and go. Now what I don’t get is, how do they know you paid? Is it on the honour system? I imagine the restaurant knows, but the wait staff working the floor? They see you get up and leave, do they run and check to see that table has paid? Or no?