Lad, it is fitting that you should bring up that argument now, since we are nearly at the one year anniversary of me having argued against you that Casti Connubii contains no such denouncement. Has a year been long enough for you to develop a response to my criticism? :)
What CC teaches is right there in black and white. It is sinful to subordinate the primary end to the secondary. If attempting to eliminate the primary while enjoying the secondary is not subordination, than nothing is.
You falsely claimed that SUBordination is not in the original text, except that it is. "due/necessary ordering toward the primary end". That is what phrase means that, being the secondary end, it must be ordered to the primary end ... correctly and appropriately translated in approved translations as subordinated. That was the big criticism of Vatican II from the conservative Fathers group, that V2 tried to make the primary and secondary ends of marriage to be co-primary ends, whereas Traditional Catholic theology has always taught that the secondary were SUBordinate to the primary. And I explained the context of your completely out-of-context use of the Holy Office ruling. That had nothing to do with any principled acceptance of NFP whatsoever. In fact, the language backs up the Church's disapproval of NFP.
I already responded to you, including one long multiple-paragraph post and several smaller posts addressing each one of your false points. I clearly addressed how your wore purposely conflating the two separate principles outlined by Pius XI, claiming that a mere physical completion of the act in the natural way was in fact identical to having the proper motive regarding the ends of the act ... which is utterly absurd and preposterous. You make now allowance whatsoever for the distinction between the material act and the formal motive behind it, which would be rejected by all Catholic theologians. This merely shows your desperation in attempting to justify this sinful activity. Please be advised that by promoting this sinful activity, you yourself will be judged by God.