I'm 100 for having trans people's sex listed as whatever correlates with their gender because the US legal system does not handle trans people well at all, plus it causes a lot of confusion when showing ID. But for education and health reasons, we need to remember that no matter what our gender is, we are still our bio-sex. Embracing that is essential to being a healthy trans person, and doing so is what legitimizes the transgender identity. Even if you don't want SRS (I'm part of that group).