The custodian shall transfer in an appropriate manner the custodial property to the minor or to the minor’s estate upon the earlier of: The minor’s attainment of 21 years of age with respect to custodial property transferred under § 13-304, § 13-305, or § 13-306 of this subtitle; The minor’s attainment of age 18 with respect to custodial property transferred under § 13-307 of this subtitle; or The minor’s death.