Excluding all males from women's loos is not complicated at all. What makes it complicated is the idea that certain males should now be allowed to share women's facilities. I'm trying to understand how a woman is expected to differentiate between the different classes of males.
Do you know why women have their own intimate spaces, toilets, changing rooms, refuges? Any clue at all?
''Complicated'' or not I have to tell you again, blanket bans are not lawful.
I also have to tell you that the terms that you are using are gender terms, and not pertaining to a person's sex. Trans women with a GRC can use the women's loo because their gender identity matches the sign on the door -''women''.
This is special pleading.
The term ''public toilets'' refers to the fact that the public can enter. The law says that a private space exists behind a closed and locked door.
The reason for the difference is accounted for by the available facilities. You choose which door to go through according to the facilities that you need regardless of your sex or gender identity.
If baby change facilities are only in the women's loo, then that is where a father needs to go to change a nappy.
This isn't hard.
The case you are making is one of special pleading for permission to exercise prejudice over people that you dislike because you found some pictures of people that you call ''perverts''. You can provide no evidence of harm or wrongdoing, but you feel that you are entitled to do this.
You have no such entitlement of privilege - we hear too much of it these days, people trying to exercise some superiority. Typically this is a feature of while nationalism, and mostly claimed by middle-aged white men (boomers).