One of my main issues with transphobia in leftist communities is that so many communists, socialists, and anarchists are part of the LGBT community, and excluding them would be shooting yourself in the foot. The smart ones are working towards the same goal of fucking porkie, just like us. I also think it is immoral to dehumanize people like that, especially if they are struggling with self-identification issues. Yes, they can be annoying, but everyone on the internet is. BUT, that is beyond the point.
Regarding feminism, women's liberation is and has been a core tenant of socialist and communist thought. Kropotkin wrote about women's emancipation, and Lenin advocated for women to participate in politics. Ocalan is a very important figure in contemporary leftist politics, and he has wrote a great deal about liberating women from the patriarchy (look up Jineology, if you're inclined).
Just my two cents.