Well, my answer would be that such a measure would not be feminist - it can't even be classified as positive discrimination since gender, unlike race, is not hereditary.
I guess you could chalk that to a "no true Scotsman" fallacy, but I'm fairly certain that the majority of people who self identify as feminist would not support such a measure - I have no numbers to support that claim, as I wasn't even aware of that party's existence.
The reductionist statement made is usually "Feminism is just about equality" — a claim quickly invalidated when you consider the Swedish Feminist Initiative political party had as official policy in 2014 that men and women will earn the same money for the same work, but men must now pay more income tax than women to address historical imbalances.