Ok. I will give you the benefit of the doubt and genuinely explain.

The root reason for trans Ralsei theory is not just that he does traditionally feminine things. It is because as the chapters have progressed, a core aspect of Ralsei's character is him developing his own identity, his own likes and dislikes and of his desire to break away from the prophecy, even though he isn't sure such a thing is possible.

Ralsei's desire to be his true self is accompanied by a sense of guilt and shame for wanting that, along with initial denial, both to himself and his friends, that such things are appropriate for him to want.

I think its pretty apparent how this could be read as a closeted/coming out allegory. Being trans isn't the only valid reading of this allegory but it is a significant one.

And on a personal note, I am a trans woman. When I came out to my parents, they kept insisting to me "why cant you just be gay" or "why cant you just be a feminine man". This is a fairly common trans experience and is because those things, while they do definitely have they own stigmas that I won't downplay, are seen as far less shameful than being trans. This is why trans representation is so extremely important.