as of the date the offense was committed) that has since been removed from designation as a fentanyl-related substance for purposes of this title and has been placed on any schedule other than schedule I or II or has been removed from the controlled substance schedules, the sentencing court may, on motion of the defendant, the Bureau of Prisons, the attorney for the Government, or on its own motion, after considering the factors set forth in section 3553(a) of title 18, United States Code, vacate the previously imposed sentence, or impose a reduced sentence on any count of conviction as if the removal or placement was in effect at the time that the offense was committed. Nothing in this section may be construed to require a court to vacate or reduce any sentence. (B) Defendant not required to be present Notwithstanding rule 43 of the Federal Rules of Criminal Procedure, the defendant is not required to be present at any hearing on whether to vacate or reduce a sentence pursuant to this section. . (b) Import and export cases Section 1010(b) of the Controlled Substances Import and Export Act ( 21 U.S.C. 960(b) ) is amended by adding at the end the following: (8) In the case of a defendant whose offense of conviction under this title involved a fentanyl-related substance (as defined in schedule I(e) of section 202(c) of the Controlled Substances Act as of the date the offense was committed) that has since been removed from designation as a fentanyl-related substance for purposes of this title and has been placed on any schedule other than schedule I or II or has been removed from the controlled substance schedules, the sentencing court may, on motion of the defendant, the Bureau of Prisons, the attorney for the Government, or on its own motion, after considering the factors set forth in section 3553(a) of title 18, United States Code, vacate the previously imposed sentence, or impose a reduced sentence on any count of conviction as if the removal or placement was in effect at the time that the offense was