Quantity based discounts for All variation products

If a customer purchases multiple variations from the same product family (e.g., different sizes/colors), we can apply quantity-based discounts based on the total units across those variations. We set this up as a mix-and-match promotion targeting the whole family (or its category/tag), with tiers like 10+, 25+, 50+. On the sales order, the system sums the quantities across the family and applies the correct discount automatically