We go back to understanding that it is only philosophical belief that any male person can become a female person. Those male people can only ever live how they 'believe' is a 'female' life. But the harsh blunt reality is that they are male people living their stereotyped view of female people.
Then we are left with understanding then that this was never an appropriate action to allow any male to enter female single sex spaces.
So, all male people need to be welcoming to gender non conforming male people in male single sex spaces. If a campaign needs to be done to make more cubicles available, then that is for male people to sort out. If a campaign needs to be done to raise awareness that male people come in all forms of presentation, then that needs to happen.
If there is actually a violence issue in the UK (and we have never seen any proof of this, just leveraging of South American trans prostitute's plights) then this needs to be resolved without making female people responsible for male people's safety and happiness.
In the meantime, if third spaces are needed, then that needs to be addressed.
We know that there are options out there. Every so often male and female trans people tell us there are knowledge bases etc that allow people to plan their outings for the day so they find the spaces they need. They are proactive about it. They are how we know that this is not a 'ALL' transgender people issue.
The point is though Itisnotyou, is that I believe that many of these suggestions were made a long time ago. And rejected over and over. And have been positioned as being hateful.
What we need is for the people who are male who choose not to use the female single sex spaces to start grouping together and sending letters to get the discussions happening if they need special spaces or programmes. But it seems that as you say, this group is just getting on with it which is an indication that they are ok with what is provided (until more people use those spaces they might need more, if you see what I mean).
So, ultimately, what we need is for the laws to be clear. And then what we need is organisations to listen to women who need single sex spaces to enforce these spaces.