"I was wondering if True Leftists criticize drug addicts (especially those that are trying to recover but are unsuccessful) for lack of willpower or other inner qualities."
I would only be worried if addicts are trying to pass themselves off as non-addicts when they are not, thereby deceiving others. The system I proposed above would make it easy to check.
"I'm approaching this especially with regards to state-controlled reproduction concerning drug addicts or individuals with addictive personalities."
In my vision of state-controlled reproduction, who gets to reproduce is decided during early childhood, specifically before they are aware that they are being selected, in order to prevent those with a stronger desire to reproduce (hence inferior) from using effort to increase the chances of themselves being selected. Drug use should not yet be an issue at that stage. However, if between selection and reproduction the selected individual becomes a drug user, the additional consideration arises of whether or not the drugs could be producing negative heritable consequences. This will depend on the particular drug etc.. It is also not theoretically impossible that some drugs could produce positive heritable consequences. Therefore I cannot answer generally. If we wanted to err on the side of caution, we could exclude all drug users. But once again, this policy must not be known by those under selection, lest those with a stronger desire to reproduce (hence inferior) deliberately refrain from drug use in order to not be excluded.
As for addictive personalities, let's use video game addiction as an example. I am not too worried about those who have to play the same video game every day. I am far more worried about those who eventually get bored with every game they try, and hence keep seeking out new games. The latter I would definitely prohibit from reproducing. See also:
https://trueleft.createaforum.com/true-left-vs-false-left/progressive-yahwism/msg13288/?topicseen#msg13288