If I have to recommend someone to attend an SSPX chapel for valid sacraments, I try to give them a heads up about issues like making sure the priest is traditionally ordained, being strong against BoD/BoB/II.
It's a rare thing to find a priest who isn't strongly FOR BoD/BoB. Some are so against it that if they find out you're a "Feeneyite" they'll deny you the Sacraments. There are others who tolerate it provided that you don't "prosletyze" your anti-BoD beliefs.
I'm actually not opposed to BoD/BoB per se. I don't believe in it, but I acknowledge that the Church has permitted the position and even at times seemed to favor it ... though it has not taught it in any kind of authoritative Magisterium. At the end of the day, the conclusion is inescapable, if you objectively look at the history of the matter, that BoD was not part of the Deposit of Revelation, but rather a theological speculation (often made for emotional reasons) that has no solid foundation other than wishful thinking. There are also some very problematic premises behind it, i.e., that somehow God can be "bound" or thwarted by "impossibility" from getting the Sacrament to His elect. That's almost heretical, and St. Augustine said that this position must be rejected if "you wish to be Catholic".
Where I have an issue is when BoD gets extended to FoD (Faith of Desire), that someone who lacks the Catholic Faith can somehow "desire" his way into it, someone who doesn't even believe in Baptism can desire it (St. Robert Bellarmine explicitly rejected the notion that you can desire something that you're ignorant about). At that point, people slide into neo-Pelagianism and effectively reject Trent's dogmatic teaching that the Sacraments are necessary for salvation. We're at the point of "Anonymous Baptism", where you can be baptized without even knowing it. This is no different than Rahner's "Anonymous Christian", which Archbishop Lefebvre articulated almost verbatim at one point.
What puzzles me is how Trad Catholics believe that non-Catholics can be saved, which has nothing to do with whether someone who theoretically has the faith and intends to be baptized can have some graces of the Sacrament supplied. If you believe non-Catholics can be saved, as 95% of Trad clergy believe, then any and all theological opposition to Vatican II evaporate.
MAJOR: There's no salvation outside the Church.
de fideMINOR: Non-Catholics (heretics, schismatics, and infidels) can be saved. [believed by most Trads]
CONCLUSION: Non-Catholics (heretics, schismatics, and infidels) can be inside the Church.
This conclusion is inescapable. If you believe that non-Catholics can be saved, then you MUST hold that non-Catholics can be inside the Church.
This in a nutshell IS the ecclesiology of Vatican II, a Church which consists not only of a "subsistent" core of actual Catholics, but also various non-Catholics outside of that core, who are separated by varying degrees of separation depending on their degree of error. You get partial Communion, etc. And even Religious Liberty traces back to this.
If someone could convince me that non-Catholics could be saved, I would have to drop all theological opposition to Vatican II, and only the problem of the New Mass would remain.