Here OP I just found this on RMS in Rickmansworth. If you read what they're saying rather than how they're saying it, their actual policies seem sensible and sound. I especially like:
"Should a pupil disclose that they are having gender identity thoughts, that they are identifying as trans, gender fluid, gender non-conforming, non- binary or gender questions, the school’s overall approach is not an affirming and encouraging one, it is a supportive and inclusive one." [followed by exactly what they mean by that].
I also liked: "We remain a girls school." Which is an excellent complete sentence. ;)
Basically it sounds like they will facilitate girls who need to explore their gender but that they also understand their duty is to act in the best interests of all pupils not just the few. And that they are not going to allow biological males to attend any time soon.
They have also specifically addressed toilets and changing rooms (all cubicles), boarding and school trips.
If we lived closer to Rickmansworth or if we move further in that direction in the future I would consider RMS actually, they sound very sensible and very aware of the fine balancing act they need to maintain.
https://www.rmsforgirls.com/wp-content/uploads/2023/03/GENDER-IDENTITY-1.pdf