Yes, the position of doubt is strange to me. Lad says he doubts between A and B yet he constantly says B is not Catholic
That's due to your inability to grasp distinctions. You evidently failed to recognized when I enumerated multiple permutations, including C, D, E, etc.
Evidently I have to say it again. What cannot be doubted is that the Magisterium cannot fail catastrophically as R&R asserts. You can argue that the Magisterium has not failed (as conservative Novus Ordites do or as XavierSem does). You can argue that it's not the Magisterium (as sedevacantists and even sedeimpoundists do). But you cannot argue a failure of the Magisterium. Even Archbishop Lefebvre was quite clear on this. That is the one constraint to which I assert that it's not Catholic. Within those limits, go to town in terms of the permutations on it.
Modern R&R, which has totally gone off the rails from the position of +Lefebvre, has totally lost its way. Do I need to quote +Lefebvre on this subject again?