I think you may be making it over complicated here are 2 simple solutions
Set a birthday that’s within limit. Does not matter if its his or not. Specify all waiters use same one for these cases and you can track its use.
or
Make it do whatever behavior you want… move the Age verification to start from automation command executed instead of order added… and put an ask question on the order added… Question can say, Does customer look like they are over 40? Yes button would bypass the birthday check but still confirm… no button would initiate the age check. Can use the same constraints looking for confirmed status or unconfirmed for the question to be fired.