From reading Lang's quoted piece, this seems good, but I agree with Dodo that whilst the proponent is a male transwoman person who uses women's single sex spaces, we have a fundamental problem with its integrity. Any hypocrisy undermines the aims and gives wriggle room to opponents (and really makes me raise my eyebrows)
Obviously children in school have particular requirements, captive and vulnerable as they are, but children also exist out of school and need single sex and safeguarded provision outside of school as well and their mothers do too.