Yet people have assumed that because I'm not prepared to spoil a vote that could be used to fight cuts to the NHS, social care and education, I can't possibly care about women's rights too.
No, I inferred (not assumed) your contempt for women and their rights from your minimisation of women's concerns, misrepresentation of our motives, and gaslighting about said misrepresentation. There are plenty of women on this thread and the thread about considering voting Tory who intend to vote for the party that they feel poses the least harm to women and I respectfully disagree with them. What none of them have done is minimised concerns about self-id.
I'm a systems thinker and I can see how self-id will have wide-ranging adverse effects upon all aspects of women's lives. To give one example, relevant to your point that we need to worry about public spending cuts:
If a female protester against cuts breaks the law in a principled and non-violent way (aka "civil disobedience") e.g. she lies down in the road or handcuffs herself to railings, she already runs some risk of being incarcerated alongside an intact male, with the risk of rape and forced pregnancy that that poses. Under self-id, the presence of a male in her prison or police cell becomes much more likely because the barrier to a male becoming legally a woman will be much lower and a legal woman must[1] be housed in the female prison estate even if said legal woman is a penis-possessing sex offender, increasing the risk of a woman being jailed with a rapist. A woman who is currently prepared to go to jail for her cause will be less willing to do so if it means sharing a cell with someone like Karen White or Jacinta Brooks and this will have a chilling effect on women's ability to use civil disobedience to protest against cuts. The loss of female-only prisons will forever stop women from using civil disobedience to protest against cuts, whether those cuts are implemented by the current government, the government we will have after 12th Dec, or any future government. You'd agree to that in exchange for a single term (because there's no assurance of a second term) of a Corbyn government? You sell women's rights very cheaply.
The effect of self-id stopping us from resisting cuts and filling the gaps caused by cuts with charity is replicated across the whole of the services women use. Consider the following:
A) Council stopped funding the women's refuge, feminists have a whip-around, oh wait, the law changed and now we have to let penis-wielding males in and the women no longer feel safe and are preferring a tent or returning to abusers over staying in the refuge.
B) Council still funding the refuge but the law changed and now we have to let penis-wielding males in and the women have moved out into tents or gone back to violent partners because "better the devil you know".
What's the difference between A and B other than in A a bunch of women ended up out of pocket? If we keep self-id out of the statute books then there becomes a point to having that whiparound AND a point to fighting the cuts to funding. If women refuse to use the service because they fear males, no point fighting for it to be council-funded, is there?
[1]: On paper, women who are too dangerous to be managed in the female prison estate can be housed in tbe male estate. In practice, this hasn't happened yet and seems unlikely to occur.