The proportionate means and the legitimate aim

[Kinsters]

The legitimate aim: To ensure that no man can say "I wasn't flashing, I was just getting changed."

The proportionate means: Some trans identified men feel invalidated. Some trans identified men are subject to transphobia in male toilet facilities.

Men take advantage of plausible deniability to sexually assault women all the time. Women don't report it for fear of not being believed. Or worse, if "trans" is involved not just not being believed but being DARVO'd into being the transohobic, bigoted aggressor. It being accepted that penises are not allowed in women's toilets and changing rooms will stop the everyday "did he really just assault me?" from being in our private sex segregated spaces.

Do add your own legitimate aims and proportionate means!

This doesn't quite make sense. The proportionate means is the thing you do to achieve the legitimate aim, so:

Legitimate aim: privacy, dignity and safety

Proportionate means: provide single sex facilities and services

Some trans identified men feel invalidated. Some trans identified men are subject to transphobia in male toilet facilities.

These are side effects of the proportionate means, rather than the means itself. They are perhaps factors to be taken into account when assessing proportionality, except that the supreme court has now clarified that the time to employ proportionate means/legitimate aim is when deciding whether or not to provide single sex services in the first place. Once that decision has been made it's just a matter of ensuring your single sex services are actually single sex. You don't need to do PM/LA again for a special group of men.

Oh I see, I was trying to get too specific.

This is the common misinformation though. It has come out in the Houses of Parliament, on Woman’s Hour from the Amnesty International CEO, etc. That the Supreme Court ruling hasn’t really changed anything and you still can only exclude “trans women” from women’s spaces if it’s a proportionate means to a legitimate aim and that they can be considered different to other men for this purpose. Stonewall law since 2015.

Nonsense. The Equality Act does not recognise "trans women" as having any special rights. Male transexuals possess the protected characteristic of gender reassignment & they may not be less favourably treated than other biological males who do not possess the PC of GR but that's it. TWAM
Female single sex spaces exclude everyone except those born female. Toilets & changing rooms are obvious places where excluding all males is required for reasons of decency, privacy, propriety etc

I know it’s nonsense, but that is what many of these people claim. They either genuinely think or deliberately misrepresent that it comes under discrimination on the basis of gender reassignment and that that somehow cancels out the Supreme Court ruling that sex is based on biological sex.