The point of Tatchell's argument, and Robin White versus Maya Forstater last week on Shelagh Fogerty re the Costa poster, and underpinning the whole of trans liberation theology, is that the science doesn't matter. All that matters is the lived experience of individuals, how people wish to express themselves, and how society as a whole and no-one within it should be allowed to do anything other than celebrate self expression.
This is a post Christian, post moralist, post generally agreed standards, post Enlightenment, indeed a post liberal, world.
Where all that matters is individual self worth, their authentic self, and the obligation of society to reflect back positively, and never judge.
It's for society to work out how to do this, including men in women's sport. Not for the individual man to ponder on the significance of stepping into that female changing room, and onto the medals podium.
This is the post modern world homing into view.