Late flights is a common thing in Hawaii. The resorts allow you to use the property, but store your luggage (or you can put it in your car if you wish). We have stayed at several Florida timeshares with the same policy. The Kauai policy mentioned above is the only one I've ever heard of that allows you to "buy" late checkout, "pending availability". I also wonder how that impacts people checking in or room changes, which are waiting to get into their rooms. Also, if you're checked out, your room-charge privileges will likely need an update (the front desk can give you a card)