IMO, it really does not matter whether Jorge Bergoglio is a material heretic or formal heretic.
I agree with this but not because of the reason you give, but because besides speculating about it, it is not up to us to judge such a thing. How long would we have to suffer such punishment? Only the Good Lord knows since he is still in charge. Heresy, even material, still requires a denial of an infallible dogma. We all agree that the jeopardized dogma is EENS and surely we can
legitimately resist the Pontiff, but we're in no position to declare him a heretic and even less so, depriving him from office, which would only happens after the Church Herself does it. God knows whether the seat is vacant, ultimately what we need to worry about is the salvation of our own souls.