The bottom line for me, and I don't try to bind other people's consciences or say they are going to hell if they don't agree
The Church binds us to believe with Divine and Catholic Faith that the public sin of manifest formal heresy per se separates the heretic from the Church. Some arguments I have seen in this thread try to place qualifiers such as "the Church has to make that judgment". These qualifiers add conditions that are not in the Church's teaching on this matter. I think a key cause in adding these conditions is because the distinction is not made between the "sin" of heresy and the "crime" of heresy. The Church teaching is that the "sin" of heresy separates the heretic from the Church. This would be the case regardless of whether heresy is classified as a crime by the Church. "Sin' is a concept regarding Divine Law and Natural Law whereas "crime" is a concept of human positive law. That the Church and only the Church can judge one to be a heretic makes the Church teaching regarding the "sin" of heresy dependent upon the "crime" of heresy. This is false because human positive law is based on Divine and Natural Law and not the other way around and more fundamentally, human positive law doesn't need to exist at all.
Everyone is bound in conscience to hold that the public sin of manifest formal heresy per se separates the heretic from the Church, and this without qualifications.