I'm happy to respect preferred pronouns and I'd want to be an ally to anyone who has made the tough decision to transition.
I don't want to pick on you Doublevacc, but I think this is an interesting philosophical point I'd like to dig into.
I am a feminist, and I subscribe to this definition of feminism by Andrea Dworkin.
Feminism is a political practice of fighting male supremacy in behalf of women as a class, including all the women you don't like, including all the women you don't want to be around, including all the women who used to be your best friends whom you don't want anything to do with anymore. It doesn't matter who the individual women are. They all have the same vulnerability to rape, to battery, as children to incest. Poorer women have more vulnerability to prostitution, which is basically a form of sexual exploitation that is intolerable in an egalitarian society, which is the society we are fighting for.
Andrea Dworkin also wanted the transsexuals of her time to have access to state-funded surgery to make their bodies the way they desired, so they didn't end up prostituting themselves to pay for it. I also agree with her on this, and I am supportive of the NHS to funding Evidence Based Treatment for adults.
However, do I have a duty to be an ally to anyone who transitions? Consider Brennan up above. Brennan sexually abused multiple girls. They are of my sex class, and subjected to sexual violence. If Brennan has their penis surgically modified, does that mean Brennan is more entitled to inclusion in the feminist movement than their female victims? Is Brennan more entitled to my advocacy?
Surely I have a choice in whom I fight for?
The question is somewhat academic as of people who say they are trans choose to have no medical treatment at all – no surgery, no drugs [[https://forwomen.scot/did-you-know/]], so Brennan themselves probably won't. But it's something we should iron out, because it's come up.
For example, the serial killer Donna (formerly Douglas) Perry killed at least nine women before having full reassignment surgery.
en.m.wikipedia.org/wiki/Donna_Perry_(serial_killer)
Am I obliged to care more about Perry because of their penis surgery than I should care about the women in the women's prison where Perry is currently housed?