There are professionals who say the PC of GR is needed because there have been instances where trans people would not have been protected if GR didnt exist. (Unhelpfully, i havent been able to find actual examples.)
It cant be include within faith because a medical condition isnt a faith.
Obviously, it cant be included with disability.
I dont understand why it cannot be included under sex, unless the aim is to treat men as if they are not men, and women as if they arent women. But judgements are showing that the PC of GR alone doesnt allow for that.
The only examples i can think of is time of work for cosmetic surgery. A man wouldn't be given paid leave for facial surgery, but a man with gender would be if its part of his identity? Or maybe dress codes at work, or name changes?
Its more likely to be the ability to change 'gender marker', to aid the GRC process. And thats where the problem is for women and girls - men with female id.
I'd question if 'gender markers' need to be changed to support the GRC process. Serveral ids are needed - bills, memberships of organisation, qualifications none of which prove sex. So why would passports and work details need show incorrect sex, when the panel would understand that anyway?
Removing the need to change sex/gender markers to inform the GRC process would maybe remove the need for PC of GR, or make GR less likely to conflict with the rights of women and girls.