JohnGrey said:... I know of no SV congregation that observes the 3-hour mitigation. SSPX, or any group using the John XXIII missal would no doubt use the same fast. This was done to appease modern weakness, and was introduced during the experimental period between 1950 - 1956.
The CMRI which is the biggest SV congregation in the world, most likely, definitely observes this reduced fast. I personally don't, but I don't say others are wrong to do so.
If Pius XII was a true Pope, as pretty much everyone believes he is, then this is a discipline that can't be questioned.
The same goes for the Holy Week changes under Bugnini in 1955. If Pius XII was the Pope, then God was still protecting what sits in Rome, and all disciplines, all changes in the liturgy were protected by the Holy Ghost. Remember what the Council of Trent says about saying the true Church can promote a liturgy that is an "incentive to impiety..."
God can use Bugnini just as he can use an immoral Pope for his own ends.
I must confess, the SSPX is more logical in this one case, at least. There is no real way to prove that John XXIII wasn't a Pope. If you say "He was a Mason," show me the proof. If you say "He convened the Council," so what? It hadn't yet been put into place, you can't assume he knew what direction it would take. Besides that, Pius XII spoke of a future Council that would be convened by his successor. If you're going to judge internal intentions based on external impressions, then you'd better eliminate Pius XII too, who said some extremely questionable things. I tried to do that once, it didn't take, so my new theory is that Pius XII was a true Pope but a weak one.
The exact line of demarcation that divides the true Church from the non-Church is not easy to spot. But where all sedes agree, if not the SSPX, is that from Paul VI on we have had nothing but non-Popes, so that everything after the VII Council was signed is null.