I sense this possibility is really what has Bishop Fellay's dander up.
The problem isn't even anymore the question of an official or unofficial deal.
The problem is Bishop Fellay's tyrannical grip on the SSPX, and his determined effort to shift the SSPX into the conciliar orbit.
The solution to the problem is to break that grip, to unequivocally and unashamedly repeat the old rhetoric of Archbishop Lefebvre. To free the priests to preach authentic Tradition.
Once his power is broken, once the priests are unafraid, gradually a parallel leadership can be given the real authority. Then the effort to take back control over the money and finances can begin, and finally the effort to root out masonic infiltrators can commence in earnest.