The Society of St. Pius X has published the General Chapter's "Common Declaration". Key passages pertaining to negotiations are below. The second paragraph is disturbing, as it a priori judges the Magisterium of yesterday and today. No doubt, there is a frightful crisis, as the Holy Father has pointed out time and again. However, "waiting for the day when an open and serious debate will be possible" is also an a priori judgment.
For this reason it seems opportune that we reaffirm our faith in the Roman Catholic Church, the unique Church founded by Our Lord Jesus Christ, outside of which there is no salvation nor possibility to find the means leading to salvation; our faith in its monarchical constitution, desired by Our Lord himself, by which the supreme power of government over the universal Church belongs only to the Pope, Vicar of Christ on earth; our faith in the universal Kingship of Our Lord Jesus Christ, Creator of both the natural and the supernatural orders, to Whom every man and every society must submit.
The Society continues to uphold the declarations and the teachings of the constant Magisterium of the Church in regard to all the novelties of the Second Vatican Council which remain tainted with errors, and also in regard to the reforms issued from it. We find our sure guide in this uninterrupted Magisterium which, by its teaching authority, transmits the revealed Deposit of Faith in perfect harmony with the truths that the entire Church has professed, always and everywhere.
The Society finds its guide as well in the constant Tradition of the Church, which transmits and will transmit until the end of times the teachings required to preserve the Faith and the salvation of souls, while waiting for the day when an open and serious debate will be possible which may allow the return to Tradition of the ecclesiastical authorities.
The full text may be read here.