tea - You have every right to have your own opinion.
"the one reason that I am happy to support trans women in women's spaces is the vulnerability of trans women"
As I asked you before and you didn't answer: Gay men are also at risk of violence from men. Are you happy to support them to have access to female-only spaces, as well? If not, why not?
"I said it yesterday and I'll say it again: to me it's clear that women and trans women are at risk from violent men. We should be standing together, not fighting each other."
We would not be fighting if they did not embark on a zero-sum game where in order for them to win, women must lose.
"if you believe that trans women are women, though, which judging by the posters who have commented on this thread, most of you here don't"
It is not a question of "belief", but of biology. Transwomen are objectively not women because they do not fit dictionary definitions of 'female' and 'woman'. See below:
Woman: Adult human female.
Female: Of the sex that can bear young or make eggs.
Other definitions you might find useful:
Man: Adult human male.
Male: Of the sex that can make sperm.
Transwoman: Adult human male who "feels like" a woman.
Transman: Adult human female who "feels like" a man.