Ready now: I think I will say something to Rabbi Abromowitz when I get a chance. There really is no reason to quote a Tshuvas Harashba L’halachah L’ma’aseh once it was completely rejected by the Shulchan Aruch and Rama. We don’t Pasken like that Rashba.
I’m not trying to say that pants are Muttar to wear. It’s clearly been accepted as something that isn’t done the vast majority of the time. I was just trying to prove that your comment that “all pants” was not 100% accurate as some Poskim are Mattir very loose pants (which many rely on in outdoor situations where a skirt will not be enough-e.g. rock climbing). It is also clear, though, that from the accepted P’sak of the Shulchan Aruch there is no issue whatsoever of Begged Ish for a woman to wear pants. That Rashba is a good Mareh Makom, but it was completely rejected L’ma’aseh.