Following the creation of the concept of legal sex, it is a basic necessity to be precise about which concept of sex is relevant to this positive action. And that is biological sex.
That does however tend to result in this political movement turning the dial to Batshit Mark 3 and insisting that female is anything, can't be defined, biological males are biological females and no one can prove it (in order to permit female people to retain any spaces/resources of their own)
The answer to this and the only answer, the end point, is 'no'. There is going to have to be the point of 'no'. And the meltdown will be epic, and the longer the lawmakers try to avoid it the worse it will be when they're forced to.