Honestly I am not sure anymore whether you @ReneeX are so convinced by a single study that you feel pushing it 2x will help (which btw mentions that "Skeptics of single-sex schooling have suggested that such schooling may increase students’ gender salience (awareness of gender in categorizations), reduce opportunities for mixed-gender interactions, and increase mixed-gender anxiety, but little evidence has been found"), or whether you are just driving a political ideological agenda.
This is in the area of humanities (not maths), where there are an infinite good explanation to any given problem. Studies of this kind can be ordered from any professor to drive any sort of ideology, and if you are any good with the interpretation of data, then even in sciences you can come to variety of conclusions depending on your assumptions, see the tobacco studies ordered by the majority of world governments in the 1950s-90s.
A quick google search will throw out an equal number of studies suggesting the opposite:
By the American Foreign Service "The common social pressures existing in coed environments are absent, enabling student development without potential distractions from the opposite sex."
https://afsa.org/all-girls-all-boys-all-good-benefits-single-sex-education
By the Stanford Review "some studies find results that favor single-sex schools. No studies have found any negative effects of single-sex education on students."
https://stanfordeconreview.com/2017/06/28/mccarey/
The great thing about MN is that we have people with empirical / anecdotal / intuitive evidence from personal experience, with whom we might either agree or disagree with. Taking a humanities 'science' paper at face value and repeatedly presenting it as gospel because it is a government ordered study makes me suspect - excuse my words here - either naiveté or propaganda.