The DEA can only oversee controlled substances which are substances that fall under the CSA
To be scheduled on the CSA a binding site study must be done, this is done for D9 not D8
D8 is illegal by the analogue act of the CSA, but the analogue act only applies to Marijuana extracts and not hemp
The above pic is from a ruling, this is the group that sued the DEA over hemp in 2004 and won
This was from that ruling