I think that not including these forms of the drugs you mentioned will entirely defeat the purpose of legalizing all drugs in one fell swoop. Aside from their scary chemical properties, you should take into consideration that the people who are addicted to these drugs are often driven to desperate situations because of their illegal status and resulting cost. Having known several heroin addicts, it is not realistic that they would reduce their intake to opium willingly even if that meant they are within legal rights to do so. The same goes for cocaine; many people graduate beyond the use of cocaine to crack because simple powdered cocaine fails to fulfill their need or because their nasal cavities are too damaged to suffice.

What I am saying is that I believe your idea of waiting for the market for processed drugs to "dry up" will inevitably mean creating a class of drug users who will continue to be persecuted until they presumably die out. This seems remarkably inhumane.