>> I think it can be shown that SSPX rejects certain dogmas of Vatican I. <<
Really? Vatican I? That is a fascinating charge. What dogmas do you see as being challenged by SSPX?
Pastor Aeternus Ch.3, On the power and character of the primacy of the Roman Pontiff:
9. So, then, if anyone says that the Roman Pontiff has merely an office of supervision and guidance, and not the full and supreme power of jurisdiction over the whole Church, and this not only in matters of faith and morals, but also in those which concern the discipline and government of the Church dispersed throughout the whole world; or that he has only the principal part, but not the absolute fullness, of this supreme power; or that this power of his is not ordinary and immediate both over all and each of the Churches and over all and each of the pastors and faithful: let him be anathema.