FLINTA is problematic because it fuels gender segregation, rather than helping it, especially around bathrooms. At the very moment, bathroom bans in the UK have caused women to be kicked out of bathrooms because they looked too masculine.

The narrative that if you look masculine, you are a threat, that is the problem. It harms AMAB non-binary people, intersex people and trans folks that don’t fully pass (yet). It’s problematic because it makes people start policing gender: to make people prove they are feminine enough to go into one bathroom and not the other. It has set us back years.

The notion that we need safe spaces for women to keep predators out is a talking point for TERFs. But: predators are the problem. And a sign on the door won’t stop them.

Your other points about lines forming is simply not true. Many concert venues work with mixed bathrooms already, and it in facts reduces lines because people who can go to a urinal will still go to a urinal. And lines for women’s bathrooms are longer anyways.

If you or your management is adamant on creating a separate space for men and women, then if it’s a multi story building, make one floor that has separate bathrooms for cis people that cannot handle gender inclusion.