; and (2) best practices regarding the detection of such substances, including such substances moving through the mail. 7. Training of U.S. Customs and Border Protection officers with respect to detecting synthetic opioids The Commissioner of U.S. Customs and Border Protection shall provide to officers of U.S. Customs and Border Protection training in detecting illicit fentanyl, other synthetic opioids, and other narcotics and psychoactive substances, and precursors to such substances, entering the United States, including training with respect to the use of detection equipment and trends in the transportation of such substances. 8. Evaluation of implementation of STOP Act of 2018 Not later than one year after the date of the enactment of this Act, the Comptroller General of the United States shall submit to Congress a report evaluating the implementation of the provisions of and amendments made by the STOP Act of 2018 (subtitle A of title VIII of Public Law 115–271 ; 132 Stat. 4073) that includes— (1) identification of potential areas of risk with respect to the entry of illicit fentanyl, other synthetic opioids, and other narcotics and psychoactive substances into the United States by mail, including any gaps that drug traffickers have found in the system established under the STOP Act of 2018, that takes into account, as relevant, the factors set forth in section 343(a)(3) of the Trade Act of 2002 ( 19 U.S.C. 1415(a)(3) ); (2) (A) a description— (i) of any significant differences in rates of compliance with that section between packages transported by the United States Postal Service and packages transported by private carriers; and (ii) that takes into account, as relevant, the way that the factors set forth in paragraph (3) of that section may affect any such differences; and (B) an analysis of how, if at all, those differences may contribute to the risks identified in paragraph (1)