The whole reason we're in this mess in the first place is because we have complied with exhortations to 'be kind'. It's spelled out in the Goodwin ruling:
... the Court considers that society may reasonably be expected to tolerate a certain inconvenience to enable individuals to live in dignity and worth in accordance with the sexual identity chosen by them at great personal cost.
See also one of the few mentions of how vulnerable female prisoners might be affected by the transfer of a male transsexual (prior to both genital surgery and GRC but with diagnosed gender dysphoria) into the female estate.
This set the precedent for the state being required to house some males in the female estate, regardless of them having convictions for sexual assault and violent crimes.
Successful appeal which overturned the Home Office's previous refusal. (2009)
No apparent dicussion or assessment of impact on female prisoners except the following evidence from an expert in gender dysphoria, Dr James Barrett of the Gender Identity Clinic, Charing Cross Hospital, who had also known the Claimant for many years, explained why living in role in female accommodation was required:
"it will become clear that she is so widely accepted as female in that unit that location in the main prison will follow. I think that such acceptance will pretty generally apply in the main prison, also, although there will probably always be a small number of prisoners who will choose to make an issue of the matter because they are the sort of women who enjoy conflict. If this patient is able to cope with protracted close proximity women of that sort I would judge her able to cope with the less prolonged, more avoidable, travails of the civilian world."
www.bailii.org/cgi-bin/format.cgi?doc=/ew/cases/EWHC/Admin/2009/2220.html