Slight word flip, it could be beneficial to have the feminine character be female, as there are different expectations from the audience. Writing good fiction requires a delicate balances of meeting and subverting the audience's expectations, so a writer who wants a feminine character is likely to use a woman in that role if they intend to subvert expectations elsewhere.
With few exceptions, gender roles, masculinity, femininity, etc are performative. Fashion for men or women changes frequently, there's nothing inherent about any particular clothing style, yet men will wear what is in fashion for men, and the same for women. That's not biological, that's performative, it's all done as social signals, we know what people expect and tend to meet those expectations. That's not something to advocate for, that's not a good thing to build your life around. Fiction is a different story, good writing uses those social cues, and is aware of how all these things impact the perceptions of the audience. In as much as gender is performative, an actual performance is the exact right place to take advantage of gendered concepts.