Edit:It should be pointed out that the press is really eager to torpedo this deal and that certain comments from Archbishop Mueller, with respect to the level of mental agreement the SSPX is meant to have of the Second Vatican Council, have been sorely misquoted, or at least toned down in later statements.
Rome remains eager to hear the SSPX's response.
When Archbishop Mueller says that the Vatican Council is non-negotiable, he's referring to those parts which reaffirm the previous Councils. Being fixated on alleged "ideological" differences, +Mueller concedes, echoing Pope Benedict and Msgr. Nicola Bux that not all of the documents of the Council are of the same weight, and that the Vatican Council is not a "super Dogma".
The following is an excerpt from Louie Verrecchio, writing for Renew America, a very balanced and fair analysis of the situation, particularly in the following.
"There was no need to call a council merely to hold discussions of that nature," he continued. "What is needed at the present time is a new enthusiasm, a new joy and serenity of mind in the unreserved acceptance by all of the entire Christian faith, without forfeiting that accuracy and precision in its presentation which characterized the proceedings of the Council of Trent and the First Vatican Council."
This being the case, if one adheres to "the entire Christian faith" as expressed in the doctrinal pronouncements that preceded the Council; then clearly one must be walking on solidly Catholic ground. This, according to my understanding, is precisely where the SSPX stakes its claim.
If this be true, then it's reasonable for us to wonder what the nature of the discord truly is.
Look, no one disputes the fact that confusion surrounds certain aspects of the conciliar text. As the communique from the Vatican Information Service (VIS) stated at the outset of the discussions "[the Holy See] leaves open to legitimate discussion the examination and theological explanation of individual expressions and formulations contained in the documents of Vatican Council II and later Magisterium."