I know additiknal space is Usually suggested as the answer and if we were talking about public toilets and toilets in the work place where there are adults using it that would be fine.
In a school however we are dealing with children. Children need adults to step in and uphold safeguarding where they don't have the ability to notice they need it or the life skills ajd experience to make the informed decision themselves.
In a school I would worry about children being forced to prove themselves as allies using them. Or being places in danger by doing so believing its solving the problem
Fully enclosed units whilst have theor advantages also present the danger of a child passing out /collapsing and no one being any the wiser. Especially as children will not necessarily have had a long time to learn to manage their diabetes asthma or allergies..
They also have the danger of being shoved in and assaulted without anyone knowing.
The first layer of protection of being able to challenge someone of the opposite sex from being there has been removed. There is also the issue of spy cameras which can now be purchased on amazon or ebay in.seconds.
Adults need to learn when it's appropriate to say know. Because even if it upsets children and makes them angry it's sometimes just something you have to do to keep them.safe.
And what may well happen is boys have the boys space and the mixed sex space and girls only have the one space.so again girls lose out on the chance of extra facilities due to biological needs they take longer and always need nore than what they have. But instead anything extra that gets built is something that will likely just he handed over to the boys.