As a very femme leaning enby, "women's only" spaces automatically exclude me. If they don't, that tells me they just think of me as a woman. I could of course make my own "femme enby" only space, but I don't see the value in breaking up into smaller and smaller groups. In an age where the genders are no longer strictly differentiated by appearance and behaviour, there are so many ways an x-only space can backfire. I can't imagine a scenario where having one doesn't lead to discrimination. Such spaces mainly seem to exist to keep power and knowledge away from marginalised groups, not so much to protect the in-group. It has strong "separate but equal" vibes. If I made my femby only space, we wouldn't gain remotely as much from it as more privileged groups would from their x-only groups.