One may say that any act of 'disobedience' puts one on the road to SVism. Like compound interest it builds up dramatically over time. Lefebvrism may be a slow version in that it reaches a stage when it has to decide whether it is serious about being 'disobedient' or simply knows better than a church it recognises. Equally, Lefebvrism may be a slow version into the arms of conciliarism when stubborn thought processes soften and out of fatigue land on an outcome that is most feared. Ecclesia Dei is such a monument to conquered heroes!
Menzingen wants a cushy niche inside Rome even if it means rubbing shoulders and being in communion with some awful companions. There one literally sups with the devil. Restoring a church (without restoring a pope) used to be a declared ambition, now discarded for Fr Pfeiffer to salvage. I doubt whether there is much yardage in the 'two popes' technical glitch, enough to suspend belief in Ratzinger's past and present transgressions. So, I would cheer Fr. Pfeiffer on and hope he finds himself after years inside the SSPX straight-jacket. Prudence, that much overrated virtue, would frustrate his obvious and much-needed dynamism. We have suffered from too many talkers from the Michael Davies camp!