For those who make the Pope the "rule of Faith"; but reject the 1949 Holy Office Letter (a minority), how do they even come to terms with Pope Pius XII's pontificate?

That is an interesting question (alltough I think there are some sedevacantists who reject Pope Pius XII).

I mean, Pope Pius XII:
- Taught NFP (which some sedevacantists reject)
- Taught that theistic evolution is permissible to believe (which sedevacantists like Dimonds consider to be heresy)
- Reformed the Holy Week liturgy (which I think most sedevacantists reject)
- Could have been aware of the 1949 Holy Office letter and Fr Feeney controversy in general

Now, I'm not saying that salvation through implicit faith, NFP and theistic evolution are not errors, I simply wonder how sedevacantists deal with that. I guess some might say that none of the above was taught infallibly by Pius XII, but John Paul II or Benedict XVI did not teach their heresies infallibly either.