Sex is binary.
There are only male people and female people when it comes to reproduction roles. There are only two types of gametes used in sexual reproduction.
“The comparison between intersex variations (DSDs) and rare developmental anomalies like conjoined twins oversimplifies the issue and misses the biological and social relevance of sex diversity.”
I don’t believe the comparison ‘misses’ anything. Because it is not as complicated as you seem to think. For the purposes of accessing female single sex provisions, there are a group of people in the world who have bodies formed around a male reproductive role but their bodies never produce or cannot utilise testosterone. There are specific and unique accommodations needed for them in society. For instance, one sub-group of this small group may in the future be excluded from female sports categories.
This is not complicated to understand at all. Activists have tried to make it ‘complicated’ and have tried to politically leverage the medical conditions of a group of people to destabilise the established science around the categorisation of human sex.
And I would suggest you revisit your on sources of information because your 1.7% figure tells us you are getting misinformation that includes many people who should not be included in that figure. Perhaps you should get better informed.
To state “If the binary model doesn’t account for all real human variation, then the model is incomplete, not the people,” seems like a mischaracterisation of the current reality. We already have a model that has the flexibility to meet the needs of those very rare people. Are you trying to say the current system is strictly ‘binary’ or that feminists are trying to force a ‘binary’ that excludes the needs of this rare group? Because that would be false.
Or did you include it as an emotional placeholder? One where you indulge in the oversimplification that you warn against others using?
Also no feminist stating that male people should not have access to female single sex provisions believes people are saying that ”male and female don’t exist”. This is such an oversimplification that it can be considered a straw man.
On the other hand, “It’s to say that not everyone fits neatly into those two categories”, is untrue because with modern technology medical specialists can indeed reliably sort humans into two sex classes. Which is relevant for medical purposes and for the people themselves to know and understand their own body to make informed and relevant decisions.
I hope this helps 😁