Might help also to describe what you think feminism is, since it’s one of those terms that is overloaded.
I once had a physical therapist tell me she wasn’t a feminist because she thought women couldn’t be as physically capable as men when serving as soldiers, and seemed to believe feminism requires treating women exactly like men.
I told her I was a feminist because I believe in equal rights for men and women, an idea she did not seem so opposed to.
Gender expression is something people should be able to choose for themselves, including in fluidity, flux, plurality, and however said gender does or does not conform to social expectation. I’m personally “cis,” I’m a man, but I also make it clear that people can use they/them to refer to me and that’s fine. I see myself as a “less masculine man.” That doesn’t mean feminine-presenting men need to use they/them, either. Pronouns are personal, and I feel most comfortable presenting myself this way. If my gender were taken from me, I would be less comfortable. It’s a form of self-expression.