JTS does not push the boundaries of frumkeit- they simply aren’t frum. Maybe decades ago they could be considered frum but not anymore. They’re the ones that ordain women and gays, and are mechalel Shabbos befarhesia! That ain’t frum by any standard.
At least YCT seems to care about most of Halacha, there are many talmidei chachamim in their ranks, and they keep Shabbos, kosher, etc. however, in regards to women’s roles in frum life they definitely push boundaries.