This feature is available in Australia where the Merchant runs an app on their iPhone to receive either an Apple Pay or in this case paying via a physical card when the limit has reached to enter a pin number for a physical card after it has been tapped on the screen.
Merchant simply taps the accessibility options which allows the user to:
2 finger double tap to repeat initial instructions,
Single tap once for 1, twice for 2, 9 for 9, and 10 taps for 0,
2 finger flick left to delete a number, and
2 finger flick left to submit pin number.
Out of all the options I've tested with this type of payment system, to me this is the best result for ease of use whilst maintaining security and privacy.
Have a listen.