FSSP priests need to interpret the Nicene Creed with Feeneyism instead of Feeneyism.Their bishops must be informed about this.
Feeneyism: It is the old theology and philosophical reasoning which says there are no known exceptions past or present, to the dogma extra ecclesiam nulla salus (EENS).There are no explicit cases to contradict the traditional interpretation of EENS.It is practical. There obviously are no known cases of the baptism of desire (BOD),baptism of blood(BOB) and being saved in invincible ignorance(I.I) in 2017.So there are no practical exceptions to EENS.Neither was BOD,BOB and I.I an exception to Feeneyite EENS in 1949 when the Letter of the Holy Office was issued to the Archbishop of Boston. The cardinals made an objective mistake.Similarly mentioning BOD and I.I in Vatican Council II (AG 7,LG 14) relative to the traditional teaching on salvation was superflous.
Cushingism: It is the new theology and philosophical reasoning.It assumes there are known exceptions, past and present, to the dogma EENS, on the need for all to formally enter the Church.It assumes that the baptism of desire etc are not hypothetical but objectively known.In principle hypothetical cases are objective in the present times.