This is the difference between the concept, and real life.
As a concept, in your head, sharing changing rooms with men, can play out fine.
But in real life, it's completely different.
Firstly it's not just the vulnerability of getting naked, its the vulnerability of all the self judgement and personal critiquing that goes into clothes buying.
If you're confident enough to walk into the common area to see the outfit from a different angle, for instance. You will be twisting and turning, wondering, pulling the skirt down, pulling the shoulders up.
The 'male gaze' is unwelcome. It's discomfiting at best. And feels like an invasion of privacy.
I'm sure we all experienced someone's husband loitering just outside the entrance, as his wife asks for his opinion. They themselves often look uncomfortable with being on the spot (and the potential for a wrong answer.)
But at least it's a scenario that is played out largely on the women's terms.
A transwoman gives rise to the potential for a completely different experience.
Because of the issue of validation.
It's where the scenario in your head and the scenario in real life part company.
As the poster above says, the huffing and puffing, all us girls together. It's all part of forcing you to validate that they are the same.
You know it, they know it. But there is little you can do about it because the 'transwomen are women' is paralysing your objection.
I don't want my private experience of buying clothes to become the means of validating a man. Especially when I have no choice.
And if I display, in any way, my disapproval, I am the one who is in the wrong.
The potential for coercive and intimidating behaviour is huge.
The only people to gain from this is domineering men. There is zero benefit for women. None.
So no thanks.