Fr. Hector Bolduc, the first Southwest District Superior of the SSPX, believed EENS in the same sense as Fr. Feeney and was a friend of the St. Benedict Center. Fr. Bolduc was the priest who arranged for Archbishop Lefebvre to meet with Br. Francis M.I.C.M. in St. Mary’s in 1980 to talk about the dogma. Archbishop Lefebvre did not believe EENS in the same sense as Br. Francis, but neither did the Archbishop consider Br. Francis to be a heretic for believing that baptism is necessary for salvation. Archbishop Lefebvre personally gave Br. Francis Holy Communion after their meeting.
Fr. Bolduc's last sermon is available on YouTube. In the sermon Fr. Bolduc accuses those who deny the absolute necessity of baptism for salvation of committing "blasphemy against God." The whole sermon should be listened to, but he talks about EENS starting at the 3:10 mark.