You should negotiate to find out if there is a limited amount that can be spent on a zap. Say limiting it to 1 sat for that button. For the IRS the unwritten rule is $600. For sales tax reporting purposes it might be a fraction of a cent. For Apple Music store the threshold is 99¢.
Discussion
I mean this is already a tremendous victory that they are treating zaps as spending real money. So now you get to negotiate with a seat at the table. And on your side of the table you have lighting fees and on their side of the table is Goldman Sax losing billions subsidizing the Apple Credit Card.