Extreme body modification decisions still do not mean that this male person should access female single sex spaces. But I think you realise this.
There does seem to be a lack of understanding though, about the needs of women and girls. Have you thought about how rarely male people are not detected as male. Sometimes instantly, sometimes it takes longer. So, putting them into a female bay means that women and girls can be re-traumatised or be distressed by the lack of privacy.
The solution was never to put those male people into a female space. As others pointed out, which other vulnerable male people should be protected by being put into the female space? None. They are out into areas where they are more protected.
Once you start to unravel the emotive reaction that seems to be associated with a male who has had their cock and balls removed and have breast development, it becomes clear that they are still male. By the exact same logic, all the people who have other extreme body modifications should be treated similarly. The men who are cats, lizards and snakes should be put where, in zoos! I mean no one would go to all that trouble to appear as a snake complete with a forked tongue if they weren’t a snake.
This is how the logic would be used in directly comparative examples. So the answer is to appropriately safeguard those patients as happens with other vulnerable patients.
Society in general needs to stop treating women as being just boobs, an orifice for a penis and a feeling. Having boobs and no cock is no reason to put a male into a female single sex space.