Ohh, that makes sense.
Generally there's two ways people go about it; realistically writing transphobia in the society, or writing as if transphobia doesn't exist. But considering the Chamber, I can see how the second would be difficult to write and still have readers suspend their disbelief, while the first is just not something most people want to write or read.
I suppose if there is one thing you could do, it could be showing the initial gender choice as cis woman/man, so trans readers know "oh maybe I want to pick nonbinary instead." Regardless, thank you for being considerate, and responding so fast lol