Under modern queer thoery, sex and gender are two completely separate properties in a person that are only linked by correllation and not causation.
Trans activists rely on the public not knowing or understanding this and they rely on the fact that people confuse gender and sex because, until 10 years ago, the two words were synonyms in the common vernacular.
But we shall not let them eat their cake and have it too. Let's hold them to their own standards: Sex and Gender are unlinked properties.
Under this ideology, arguing to use the wrong sex seggregated space is still wrong because the trans individual deos not meet the sex requirements for the space unless they have had cross-sex surgery.
You can't use "gender" to justify accessing "sex" seggrageted spaces because the seggregation and reason for the seggregation has nothing to do with gender, it is related to sex.
In fact, all sex seggregated spaces and activities are inherently trans inclusive because as long as the sex requirements are filled, the gender doesn't matter.
I.E. Female Men use the females bathroom, because it's for females not "women", male women use the males washroom because it's for males not "men"
This argument is supported by the fact that gay men/women have always used facilities for men/women accordingly.
i.e. Their gender made no difference whatsoever as to the correct facility to use.