The E-seal has worked on the market for more than ten years. Why don't Customs use RFID E-seal? Only one reason that the E-seal price is too high. The shipper and logistics will add more cost so the E-seal price is very important. Many E-seals have some bugs that is very esay to tamper. If you want to use the E-seal, you must chose the low cost and passed ISO 17712:2010 High Security Testing.
Don't choose Seal tag because it doesn't have any security structure. It just provides the identification on the seal.