The Eleventh Circuit has determined that the immigration consequences of a drug offense are established by comparing the state statute of conviction to the federal drug schedules in effect at the time of the conviction, not those in effect at the time of a subsequent adverse immigration decision (such as a denial of naturalization).
The full text of Morfa Diaz v. Mayorkas can be found here:
https://media.ca11.uscourts.gov/opinions/pub/files/202110763.pdf