Radical feminist theorists do not seek to make gender a bit more flexible, but to eliminate it. They are gender abolitionists, and understand gender to provide the framework and rationale for male dominance. In the radical feminist approach, masculinity is the behaviour of the male ruling class and femininity is the behaviour of the subordinate class of women. Thus gender can have no place in the egalitarian future that feminism aims to create.
Sheila Jeffreys, Gender Hurts: A Feminist Analysis of the Politics of Transgenderism