Look....you started off on a bad note here because you wanted to shop for a jurisdiction. You cannot do that. There is also no state that favors mothers over fathers.
However, I do understand the position that you are in, and I am going to give you more encouraging advise than you received from the others.
If its heroin, there is almost no chance that he is ever going to go to court for visitation/custody. He won't have the money to hire an attorney, and if he tried to go it alone he won't be able to keep track of court dates or anything else. He is either going to crash and burn and end up in forced rehab, or he is going to end up dead. Heroin is that bad. There is also virtually no chance that there isn't going to be eventual hard evidence of his drug use. My ex's cousin is a heroin addict, and believe me, you have little to worry about legally.
Keep doing what you are doing. However, if he ever gets sober enough and does file for visitation, then its going to be up to you to prove that he has this problem (with hard evidence) so that the judge will order visitation to be supervised....and you will have no choice but to follow the court orders. Therefore if (and more likely when) he falls off the wagon, you will have to rush back to court to get the orders modified.
Also, for his sake, you really ought to tell his family what is going on. They are the ones in the best position to get him some help. The family of my ex's cousin has managed to keep him alive, with long periods of sobriety...but its a very tough battle...and eventually its going to kill