The best illustration of how the SSPV changes Catholic Sacramental and Moral Theology is their (read: highly!) "doubtful" opinion on Thuc line Consecrations (which, of course, are undoubtedly valid), to quote this site:
http://www.thefourmarks.com/editorial.htm"2. Bp. Kelly “doubts” the valid consecration of the reknown theologian Fr. Guérard des Lauriers, O.P., since it was after Palmar. But to doubt his consecration, one must believe that this theologian –said to have penned the Ottaviani Intervention-- didn’t notice that Abp. Thuc was too senile or mentally disturbed to adequately function as minister! That’s what Bp. Kelly bases his doubts on … Of course he wasn’t there, and in fact, the SSPV had not yet been formed.
But that’s why the SSPV remain severed from these Catholics. That’s why a SSPV policy forbids giving Thuc-line Catholics the sacraments: because Bp. Kelly isn’t sure the archbishop was mentally sound. Although he multiplies words, this is the whole of his argument.
Like Thomas and the other doubters, the SSPV say they lack sufficient proof. Their argument runs like this: Our doubts are strong; we must decide who and what is credible, and who are true Catholic priests.
I’m sure I don’t know
Where there is doubt, the Church brings certainty. Doubt is the attribute of the confused, not the clear-minded. For, if one forbids discussing a doubt he has made a point of publicly expressing, it does not seem like he has doubts. It seems more like: he must not want answers or reasonable solutions."
The parallel to what has been called "sede-doubtism" by some should be clear! We doubt it, therefore it is doubtful, therefore no formal Pope [to some]! Therefore, no Priests, no Bishops in the Thuc Line! SSPV-sede-doubtism-and-sectarian-subjectivism-on-steroids!