Feature Request: Subsidize delivery for certain radius

[rumi]

Hi - if we're using Postmates as our courier for Square Online orders, we have the option to subsidize a part of the delivery order. We would like to subsidize it *just* for those within 1 mile of our restaurant, as their delivery fees are fairly high because of the $4.20 flat fee. We'd like to pay $1 or $2 of their delivery fee without having to subsidize the customer 3 miles away who is paying a very reasonable delivery fee.