I agree about the name change being reasonable for teachers to accept. I also think that a choice of uniform is appropriate.
However lying about a child’s sex to the child, to other children, to other parents, using wrong sex pronouns, wrong sex changing rooms for PE or swimming (if there are changing rooms at all at this age), wrong sex toilets etc is all too far in my opinion. Schools don’t usually go so far as this to accommodate minority beliefs. Can you imagine if Jehovah’s witnesses demanded that Christmas and birthdays not be celebrated at all in the school, or vegans requiring that no animal products were consumed in school etc It is unreasonable to expect the rest of the school community to behave as if they believe entirely in gender identity ideology- by which I mean that subjective, fluid gender identity is paramount and objective, immutable sex is irrelevant. I don’t know how the C of E has managed to incorporate gender identity into its version of Christianity so comprehensively and now believes it is right to impose it on children who are trying to make sense of the world.