Vatican I was a dogmatic council and specially addressed papal infallibility. Vatican II was a pastoral council (no dogma defined, no infallible teachings)
VATICAN I PRODUCED ONLY ONE DOGMATIC CONSTITUTION AND VATICAN II PRODUCED TWO DOGMATIC CONSTITUTIONS. SO VATICAN II IS MORE DOGMATIC THAN VATICAN I.
MUCH MORE VATICAN I TEACHES THAT THE POPE IS THE SUPREME HEAD OF THE CHURCH AND NOT LEFEBVRE AND HIS SCHISMATIC SUCCESSOR. SSPX AND SEDEVACANTISM ARE ANTI VATICAN I AND THEREFORE ANTI TRADITION. THEY PRETEND TO BE TRADITIONALIST IN ORDER TO FEED THEIR OWN CANONICAL TREACHERY.
WHO IS THE DEVIL WHO TOLD YOU THAT THE ECUMENICAL COUNCIL IS REQUIRED TO DECLARE A DOGMA BEFORE IT CAN BE CONSIDERED DOGMATIC? THE SSPX IS NOT DOGMATIC BUT PROPER FOR DOGS BECAUSE IT IS POPELESS.