There's audio of a discussion between Br. Peter and someone discussing the
te igitur, which is worth listening to. The basic premise is that this prayer is supposed to show unity with the chair of Peter, not the man occupying it, which is accidental.
Further, John Daly noted that it's no different than the
te igitur in English Masses which mention the King of England, an Anglican heretic.
It is worth noting that in the Sarum rite, then in general use in England, the King is named in the Canon, so that St. Thomas More not only received the Holy Eucharist from a priest who had sworn the Oath, but assisted at Mass in which Henry was actually named in the Te igitur.
https://bit.ly/39054liAnd St. Vincent Ferrer offered Mass while naming an Antipope. Were his Masses also sacrilegeous?
Precisely. St. Vincent during the Western Schism is another great example of the te igitur. Sure, the non una cuм dogmatist could say these antipopes were "orthodox", but their orthodoxy doesn't matter when they were not Popes to begin with. Therefore, by their logic, St. Vincent is still committing a sacrilege. Its ridiculous.