There is the issue of the airport tax. You must have a sticker for paid tax on the boarding pass in order to enter departure hall. If you are not normally suppose to leave the secure area, your boarding pass will probably not have this sticker and you'll be forced to go to ckeckin/ticketing to get one and probably pay the tax (taxa de embarque) of $36 for international departure. Which, even if you don't mind paying or don't need to pay, will be an additional delay.