I personally don't like the Chihrio is trans headcannon.
And it's not because I'm transphobic I have nothing but support for them and hope that their happy.
But why I don't like it is because I feel that it just erases there whole character motivation.
The only reason why they were crossdressing was so that bullies would stop bullying him for being to feminine.
And he hopes to one day to be strong enough to be able to tell everyone.
But I feel it's just disregards his whole backstory.
I'm fine if headcannon it and this is just my opinion on the headcannon.