This is not about Church infallible definitions, but more concerns the Church indefectibility. It really is a matter of common sense. Holy Mother Church cannot give us invalid, false, evil Sacraments for our spiritual nourishment. That would be inconsistent with Our Lord's promises, and a complete defection of the Church's Sacred mission. "The indefectibility of the Roman Catholic Church is the teaching that it will endure to the end of the world and never become corrupt in faith, authority, morals, or sacraments. In other words, the Roman Catholic Church will always be the proper representation of Christianity even though its members may err".
I don't imagine that anyone could possibly disagree with you here, Holy Mother Church most certainly cannot give us invalid, false, evil Sacraments for our spiritual nourishment. Our Lord gave us the sacraments, that's how we know they are true, Holy Mother the Church is the keeper of the same sacraments that were given to the Church by Our Lord. Thankfully, the pope is not the Church.
If you want to wholly reject the Novus Ordo Sacraments, then you need to also wholly reject the Authority (in the monarchical Catholic Church, hinges upon no one but the Pope) which promulgated them. Otherwise, there is no consistency but only ambivalence, which is the problem with the SSPX.
But of course, again, I cannot imagine that anyone could possibly disagree with you here either. The popes' authority does not extend to changing the sacraments. I would have to listen to Fr. Hesse again to find out which pope said that there is an oath that popes take, saying that if he were to change the sacraments, that "Almighty God will not have mercy on me" or words to that effect. But it's not as if he can't do it. He can do it alright, and imo, he is paying for it.
Of the many problems with the SSPX, I believe at it's core is it's dilution of the dogma EENS.