You can make this recipe using a frozen rack of ribs! If you're planning to do this, prep the ribs before freezing by removing the membrane and cutting into three sections. You can also rub with the dry seasoning mixture before freezing, to make it less work later.  When you're ready, follow the recipe as-is, adding an additional 8 minutes to the cooking time on the instant pot. Double check that they're cooked through once done. The ribs should be falling off the bone tender.