I think cases have to be looked at on an individual basis, the hypothetical one you described Trisher, I'd say a woman's prison would be the safest place.
Problems arise when lines get blurred, particularly with an evolving dilemma. Surely some common sense should prevail though, any individual who has been a previous sex offender against women, such as Karen White, an entitled Karen if ever there was one
should not be placed in a women's prison. The rights of vulnerable women, such as those in refuges who have suffered at the hands of men already should be paramount over those of any biological man wishing to identify as a woman. I did read about an incidence of abuse in a refuge in Canada carried out by an "opportunistic" transwoman, and whilst it may be rare, one case is one too many. Why should any woman who is already scarred from previous abuse have her safety compromised in what should be a safe sanctuary. What most women fear is the occasional "opportunist" among the transwomen population per se, particularly when accessing female only spaces and whilst I imagine it's not unknown that a small proportion of women could be predatory, I've yet to hear of say a young girl being assaulted by some random woman in female toilets, I have however heard of girls being followed in and being assaulted by a male and similarly boys being assaulted by males in the men's toilets. Women are naturally cautious about "biological men" who identify as women sharing spaces where they would feel exposed. Someone posted up thread the number of assaults that have taken place in changing rooms at swimming pools, that are accessible to both sexes. It's very striking how the problems all seem to stem only one way, men transitioning to women rather than women to men and in those cases one can't help concluding, whilst not wishing to slur all men, aggression and entitlement is more likely to be a masculine characteristic
Am I alone in hating the unnecessary prefix "cis" A while ago, a friend of mine had to fill out some sort of form at her place of work which had a tick box section as to what sex the participants described themselves as, "cis woman" was one option, friend said she had no idea whether she was one or not, because didn't know what it meant. Neither I imagine do most of the population.