I attended Low Mass at an SSPX chapel yesterday. There were no Leonine Prayers--instead we were to recite some prayer to St. Joseph.
What is this about? We were confused.
All you need is justification for the omission...
332 CANON 451 [Private]
In connection with the prayers after Mass, we wish to remind
you that only a serious reason would justify the omission of the
usual Leonine Prayers...
Perhaps a prayer to St. Joseph is considered "a serious reason"
in the SSPX, after all, this is the month of St. Joseph, and +Fellay,
et. al., are doing a worldwide consecration of the Society (that is,
what's left of it) to St. Joseph -- that would be on Tuesday the 19th.
This will be the second time in 55 years that St. Joseph has been
used as an excuse for Modernization, if I'm not mistaken.