Isn’t that what it is to be a philosopher?
But seriously, I don’t think supporting their rights and giving primacy to their self-identity entails accepting their ontology or metaphysics of mind. Some trans people may be dualists, and I think they’re wrong to the extent that they are. But I don’t think it’s condescending to disagree with someone about that. Trans people have no special insight into the experience of being a mind, so unlike e.g. their statements about their most appropriate sexual social role, they aren’t the local expert on the nature of mind. Nor are they inherently more expert on the ontology of sex (though I imagine many become significantly better versed in the philosophy and biology of sex in seeking to understand and explain their experiences and defend their choices).
But in any case: what are we to take away from the physical aspect of some people’s dysphoria? Is that to say that it isn’t social? I’m not sure that that follows. People have a relationship with themselves as a social being: we choose (within our ability) a haircut, wardrobe, posture, style of speech, etc. When someone doesn’t like their body, it’s largely about its social appearance: it doesn’t look like they want it to look. I don’t think having an Adams apple is something you feel internally, rather you feel it externally (i.e. with your hands) or see in the mirror. That is to say, a lot of the way we interact with our own bodies is social, to the extent we evaluate them as representing who we want to be socially.
I don’t think that’s the only way in which we relate to our bodies; people can evaluate themselves in terms of strength and flexibility and coordination in non-social ways too. But note that the people you quote aren’t talking about the many internal or mostly-functional ways in which men’s bodies differ from women’s. They aren’t saying “my bone density is all wrong!”, they’re pointing to prominent external features, things that they can see in the mirror, and that other people would notice immediately, that mark them as not the sex they want to be seen as.
But you don’t have to pretend to see, you do see, immediately. When you meet a coworker with long hair and a dress and a blouse and earrings and makeup, you see immediately what they are trying to tell you about their social sex. I don’t even have to tell you what social sex it is, because you know from a superficial description what sex it is. If we put those superficial indicia on a toaster, you would know immediately that we’re trying to convey that the toaster has that social sex, and if you say things like, “Oh, Ms. Cuisinart Metal Classic CPT-180, aren’t you looking lovely today!”, everyone will know why you’re saying that, but if you say to the dressed-up toaster, “Hey bro, you check out that football tackle last night?”, it will be seen as incongruous.
What is invisible about that?