So far the two arguments:
1) it violates the strict letter of the law
2) it's un-feminine.
#2 is very difficult to argue one way or the other, since it's at least partly subjective. I personally think that it's possible for this kind of ensemble to be quite feminine. But I'm not going to argue with that, since it's not an argument that can be won. I believe that the flow of a skirt, despite the leggings underneath, suggest femininity.
#1, that it violates the strict letter of the law. Indeed, this seems to be the case. Well, I take a step back from that, it was never any kind of law, technically speaking, as in the Church never formally legislated this. But I accept this in principle, using the term law loosely.
But I did not say that this was in keeping with that rule. I merely said that I felt that it was modest. I was digging behind the REASONING for the law, and seeing if it applied to this relatively new type of outfit. You see, fashions change. Just as it's conceivable that new fashions would be introduced that are in fact IMMODEST, despite the fact that they are not explicitly condemned by the law (since they were not foreseen), so also it's possible for some fashions to emerge that are not actually immodest, despite being in violation of the letter. Unfortunatley, the Church has been silent on this matter since I believe the pontificate of Pius XI ... due to the Novus Ordo degeneracy, so we lack the authority of the Church on this particular issue. So we have to apply the principles to new circuмstances that were not foreseen at the time based on the PRINCIPLES behind them, i.e. based on the spirit of the law.