If I add this column do I need to re-add all of my add to cart buttons on the many pages of static products? i.e. if I add this column to the cart and then have all of my product page having old add to cart behaviors that do not include this column will there be a problem? Can I set the default taxable universally to "taxable"? I only need this one item (the donation) to be untaxed. Thank you.