the wierd listings come down to the risk of chemical abuse...
There are only a very limited scope of use for LSA (other than LSD cooking) so its not to much of a concern as identifying a LSD cook would be easy from LSA purchases...
Where as bromobenzene has millions of uses and could be used and abused many ways so it is subject to higher monitoring.
If that makes any sense....
Thats my thoughts anyway, just my ideas on the scheme of the chem lists.
-AC