On moderation
We completely reject the accusation that we treat gender-critical feminists differently to our other users. If anything we tend to spend much more time explaining why things have been deleted on FWR than elsewhere and trying to help users avoid deletions and strikes.
You've written a whole extra set of rules for gender-critical feminists! How is that not treating us differently? 
Could it be that you're having to spend a lot of time explaining deletions on FWR because these extra rules are so difficult to understand and comply with?
We know what we want to say, we know how to say it clearly, we have no wish to be deliberately offensive or to harass anybody. Yet we are prevented from expressing our views in clear, ordinary language.
We have to tiptoe through what feels like a minefield (e.g. too generalising - BLAM! too specific - BLAM!) avoiding all the Bad Words, including some which are not mentioned anywhere in the special rules - what's the deal with 'TRA'? What's the deal with
? I know you don't want to make a simple list of banned words, I understand why and I think that's wise, but can you not understand that the current special rules and the way they are applied leave a lot of us feeling like we're treading on eggshells?
If Maya's case means anything it means that we should be allowed to express our belief - that sex is immutable and important - in clear, ordinary language. It doesn't give us a licence to harass anyone, everyone is clear on that, and IMO that should be the bottom line - does this post amount to harassment?
Does it violate someone's dignity, or create an intimidating, hostile, degrading, humiliating or offensive environment for them, based on their protected characteristic of gender reassignment?
www.legislation.gov.uk/ukpga/2010/15/section/26
Unlike non-crime hate incidents, the threshold for unlawful harassment is not subjective. The perception of the complainant is important but it's also necessary to take into account all the surrounding circumstances and whether it's reasonable for the unwanted conduct to cause the complainant to feel harassed.
As you say, Mumsnet is an inherently female-centred and feminist space and we have an honourable history of supporting and promoting feminist viewpoints.
Those are the surrounding circumstances.
Is it reasonable for someone with the PC of gender reassignment, or with a protected belief in gender identity, to say they are being harassed because they have deliberately come into a female-centred, feminist space and have read posts from women expressing their protected belief that sex is immutable and important, in clear, ordinary language?
I don't think that's reasonable, I don't think that amounts to harassment and I don't think such posts should be deleted.
Obviously personal attacks are different and may amount to harassment but that's already well covered in the general talk guidelines.