Combine cream cheese and butter in a large bowl. Combine with a handheld mixer on high speed until fluffy, about 1 minute. Add coconut extract, salt, and 2 teaspoons of coconut milk and mix just until combined. Add powdered sugar, 1/2 cup at a time, beating on low speed until just combined before adding more. After all the sugar is added, increase speed to high, and beat until smooth and fluffy. If the frosting seems too thin, add more powdered sugar, a couple of tablespoons at a time. If it seems too thick, add more coconut milk, one teaspoon at a time.