We need this to work with shopify pos please

To create a seamless experience between our POS and online shopping, and actually take advantage of automatic discounts through Shopify POS, we want to be able to stack loyalty rewards (i.e. $10 off) on top of a purchase that is already discounted (clothing at 50% off that day). There are multiple stacking apps that allow stacking for online orders, but 99.99% of our current sales are in person, so we need stackability on the POS.