I haven't RTFT, so I'm sorry if I'm repeating something already suggested.
My local swimming pool was rebuilt, replacing the single-sex facilities with a mixed-sex so-called "changing village".
It is now a male-dominated space. When I was still going there almost every day, I alerted staff to sexual harassment going on several times. It got so bad, a member of staff was sent to supervise the changing village at most times, just to prevent this from happening. But if you asked the management, they would tell you nothing ever happened.
I didn't know then to make sure to file an official complaint and it's became such an uncomfortable experience that I stopped using it completely. I tried again just before Covid hit, after staying away for a few years, and it's even worse. First thing I saw coming in was a sign saying that you were not allowed to walk around naked (swimming trunks must be worn or something like that). Dude getting changed leaving the door open, that kind of thing, too.
But here's the thing: I use a swimming pool in my parents' hometown. It also has mixed-sex changing rooms. They are designed in a way that prevent harassment by denying people the opportunity to hang around. Not a changing village design. (I'm not saying it's foolproof, but it reduces the risk.)
It works really well and I've never felt unsafe or uncomfortable in there. Neither has my mum.
So adding to the good advice you've already received, my advice would be to look at the proposed layout and if they are determined to go ahead with mixed-sex facilities, point out to them that there are layouts that provide opportunities for harassment and layouts that encourage loitering and layouts that make certain cubicles unsafe (out of sight, around a corner etc) and then ask them to show that they have assessed their proposed layout in terms of user safety specifically looking at harassment and assault.
My swimming pool changing village cubicles have large gaps at the top and bottom. There are bars across the top to prevent someone from climbing on the bench and looking over the dividing wall into the next cubicle. But the bars are spaced so far apart, it's easy to hold a phone or a camera up and angle it into the next cubicle (the bars are at least 5 inches apart). Nothing blocks the gap at the bottom.
So I'd say study the proposed layout and make suggestions as to how they could improve things if your other efforts fail.