Maya Forstater

... Or does it put these two categories of people together because they both share a common characteristic "women" which all women (whether bio male or bio female) have, but eg non binary females don't have (is there any proof of this thing? How do I know I've got it?)

If we're using a definition you're a woman if you really feel like a woman, whatever that means to you, does the question "how do I know if I've got it?" make sense? You tell me, do you feel like a woman? I guess: yes.

I can't pretend to understand what it's like to be born in a male body and really feel like that's the wrong gender but I believe it's a real thing that should be respected not shat on on grounds of your preferences regarding analytical categories.

Empathy is good. Also for women in prison who have been victim of sexual assault whose PTSD is set off if male prisoners housed w them. For female students who lose out on athletic scholarship because male bodies run faster...

... For muslim woman who can't use women only swim if ppl w male bodies also there. For young lesbians being told their sexual orientation is bigoted & to get over not wanting male partners. I agree gender dysphoria is real, but so are impacts on women if gender id overrides sex

I don’t know why you are rehearsing these arguments with me. I haven’t expressed a smidgen of disagreement with them. I have asked what practical difference to the feminist cause, away from these edge cases you mention, in fields of education, tax etc., adopting option B makes.

Because (as I understand it) the argument you are making for Option B (let's fudge the clear category of sex and call it gender identity) is one of compassion to individuals with personal vulnerabilities

It’s not a fudge, it’s a different choice. The fact that compassion also suggest e.g. women with PSTD in a shelter shouldn’t be forced to share it with a male, is completely consistent with everything I’ve written.