As I understand it, there is no "transition." Gay men are picked up of of the streets and offered a stark choice: be hanged on the gallows, or accept a sex change operation. If the later choice is made, it takes place immediately. No HRT, no RLE, etc. And then you are thrown back on to the streets. No aftercare, no HRT, even ex post facto. It is basically a form of castration of homosexuals, but because of various Islamic interpretations, if you are a homosexual "bottom," you really are a woman, and therefore should have those front-door sexual organs and be treated liker the inferiors that other women are treated in Iran.
As others have said, it is not an acceptance of TG, it is resolving a perceived problem with homosexuals. The Nazis had more or less the same policy, but without the choice. It was just death for all of them. So, as we can see, fundamental Shi'a religion is more humane than the Nazis.
Believe that?