How is this not enough? This is straight from the light novel spinoff about her. She gave herself HRT by sheer force of will, and you still argue that is cis behavior?
Yes, yes I do. Because when one calls themselves a boy that needs to be respected, because the key part about identities being valid is how people say what they are, not that they "don't act entirely cis". Again like I said before head-canon away but don't force it on others or attack people for following canon, or even god forbid enjoying and identifying with felix as a Femboy.
Also that idea of people "not acting cis" does indeed violate the Egg prime directive, I sincerely hope you don't do that with real people because it can end up being very hurtful and disrespectful to them. It's important to look at other people's gender as something personal and specific to them, and not something that can be semantically categorized and resolved without taking their feelings and how they identify into consideration.