You may be the first honest neo-SSPXER to have posted on this forum.
Until your arrival, all your predecessors have attempted to camouflage the change, whereas you rejoice in the changes openly and unapologetically.
Your honesty is refreshing, even if your conclusions are erroneous.
As regards Bishop Tissier’s position (ie., the old SSPX position) being reminiscent of sedeprivationism, you are confused by him using a material/formal distinction, but miss tgat where the sedes apply that distinction to papal authority, Tissier is applying it to Church membership.
That is a fundamental difference, and the proof of your misunderstanding is that the article was published by Avrille, who are tenacious opponents of all forms of sedevacantism.
Indeed, I see no point in attempting to create a false illusion of continuity in regards to how the SSPX operates today compared to its foundational principles decades ago. The differences are there to see for all as can be said about the discontinuity created by Vatican II or rather ita interpretatiom compared to how the Church was prior to it. It is best to view these issues realistically and attempt to solve their problems with a spirit of intellectual honesty.
I agree His Excellency Bishop Tissier applies the material/formal concept to Church membership and not to post Vatican II Papal claimants, but the underlying methodology used to do so is nonetheless strikingly similar to that used by the Sedeprivationists. It is an attempt to synthesize what is fundamentally at odds when interpreted in the light of our current situation. There is simply no precedent for it and is thus necessarily an innovation.
There is no reason to view the Church as divided in the way as does Bishop Tissier, for that ends up creating a sort of schismatic Church. While I agree that Vatican II, when viewed in the fashion of a superficial externality, can be seen as a robber council promulgated by heretics, infidels, and apostates; it is also true that it won't be going anywhere any time soon and we must therefore deal with it as it presents itself if we are to remain in the Church. It presents itself as a pastoral, non-dogmatic council that seeks to engage with the modern world in its own language. That being the case, as the council itself states, gives it an infallible interpretation that springs from its own authority being a council of the Pope and Bishops. That self infallible interpretation being that the Council did not seek doctrinal change, but a restructuring of old doctrine in new language.
While there is undoubtedly an issue in this sort of interpretation when post conciliar events are seen as contradicting the so called spirit of the council; it remains nonetheless the best way foreward at time being. It does not risk schism, does not reject authority, and does not seek a heretical and modernistic reorientation of old dogmas.
The Catholic system is based on authority and thus I humble myself and resign my spirit to the God given authority of the Holy Church and its pastors, the head being the Holy Father.