While the MHT (under Bishop Sanborn) is indeed the only established seminary to offer the old Holy Week, it seems to strike out on several other issues that you mentioned: they condemn the attendance at "una cuм" Masses (or even mere confession to a priest belonging to such a group like sspx even if the priest is secretly non-una-cuм) as a mortal sin. They also are quite polemical regarding Holy Week, the Feast of St Joseph the Worker, and the cassiciacuм theory. The CMRI does not take hardline stances on those issues but indeed uses the reformed Holy Week promulgated by Pope Pius XII.