With that list above of possible problems to be solved, it does become rather clearer that those problems being raised with the women's estate as the solution largely serve the purpose of justifying males being in the female estate.
Without those problems, it is simply the validation issue: a belief that a male born person who states their gender identity is a woman has the right to have that identity believed and validated by being treated exactly in the way of any female born person.
The problems linked to male prisoners placed in the female estate are all ones for female prisoners, and while the potential problems suggested for male prisoners are given huge discussion and consideration, the problems for female prisoners are in comparison barely mentioned.
The key problem is rather like the one presented by the theoretical statement "entitlement to a sexual partner is a human right". On the surface it may in itself sound reasonable to debate: it is indeed a very sad thing for someone to not have that experience in their life, and there would be many very sad personal experiences from those who could share the hardships of this.
However when this idea is unpacked, there is the realisation that in order for someone to have a legal entitlement to a sexual partner, there must by extension be a legal compulsion for a system to provide people necessary to the achievement of this entitlement. And this is the rub. Ethically, can one group of people be used and compelled in this way to meet the needs of another group? Does the vulnerability and distress of some justify such treatment of others?
These are the questions really under debate in this issue.