The change in the language of the Preface (quoted above) reflects a move from direct and clear signification in the traditional Rite toward indirect and ambiguous signification in the New Rite.

And you have the "probable opinion"/"positive doubt" issue backwards. There is no doubt at all about the traditional Rite. It is valid. It is not my "probable opinion" that this is the case. It is dogmatically certain. This is what the Church has always taught. I don't have to prove this.

You are the one holding a "probable opinion" that the Novus Ordo is valid. You think your opinion is probable because, as you say, Jesus would not "leave us orphans" (which is true but you misapply the phrase to this case). The burden of proof that the Novus Ordo is valid is on you. Until you can prove this with a dogmatic statement from the Church, you theory can be nothing more than a "probable opinion."

The Church says that I don't need to prove my "opinion" that the New Rites are invalid. The fact that they are significantly different from the Traditional Rites casts sufficient, "positive doubt" on the New Rites. I don't need to have certainty about the New Rites. I am required to avoid them simply because they signify something substantially different from the traditional Rites.

So, in order to follow the requirements of Catholic moral theology, we must ordinarily receive the Sacraments from a minister who is certainly valid (the traditionally-ordained Priest), and only in extraordinary circuмstances should we consider receiving Sacraments from a minister who is only probably valid. 

But you flip this on its head because of your "leave us orphans" theory. You naively accept that the Church (the true Roman Catholic Church) is identical to the entity infiltrated by Freemasons who inexplicably changed the traditional Rites. You are living in a false reality.

The Novus Ordo is a test, allowed by God. You are failing that test because of your human attachments and lack of clear reasoning. Please pray about this and ask for God to give you the humility to see the Truth before it is too late.

Borat continues to deliberate conflate terms, and invert their meaning, as do the SSPX in their overall gaslighting attacks.

Any kind of prudent doubt suffices to administer conditional ordination, per Canon Law.  That threshold is quite low and excludes merely irrational doubts, and negative doubt.  If a reasonable, intelligent, well educated Catholic priest or bishop concludes merely that, "well, they've monkeyed with the Rites, including the essential form declared by Pope Pius XII, in addition to removing all mention of sacrifice from the Ordination Rite, which Pope Leo XIII taught invalidated the Anglican Rite, and the Rite of Episcopal Consecration is barely recognizable ... so give who these people are, the same ones that bought is everything it is that caused is to break off from the Conciliar Church, let's just say I don't trust these same bad actors not to have vitiated the Rite"

Ignore the nonsense from SSPX where they conflate the grave sin of repeating the character Sacraments with a conditional administration thereof.  In the latter case, there is no sacrilege, and as long as you have some reasonable ground to conclude that they might be invalid, conditional ordination is at the very least permissible.

So, as pointed out many times, and ignored by the Troll Borat ...

Worst case scenario for the ones holding to the positive doubt position, if they're wrong, the bishop has wasted 30 minutes of his time, but, even then, the faithful whose consciences are troubled by the New Rites can be put at ease, and there's zero way that it would be sinful and condemned by God to engage in this practice for that reason alone, especially when there is in fact something there, and not just irrational negative doubt, i.e. the worst case is that you make an error in judgment, which would most certainly be offset by the motive of charity, echoing where St. Paul said that he would refrain from eating meat offered to idols if only to avoid scandalizing the weak.  If even in your great wisdom you consider the faithful to be wrong, as St. Paul did about eating meat, charity alone would require undertaking the conditional ordinations.

Worst case scenario for the ones holding to the "undoubtedly valid" position?  Faithful receive invalid Sacraments, possible souls lost, and grave damnable sins on the part of those clergy who attempted to force their decision on the consciences of the faithful.  In fact, even if they're RIGHT, they would still be guilty of grave sins against charity by subjecting many faithful souls to troubled consciences.

So, this debate here is 1000% NO CONTEST in favor of a requirement to perform conditional ordinations.  Period.  There no argument.

... unless the entire reason you're taking this position and forcing it on others' consciences is because first and foremost you cannot jeopardize your relationship with the Modernists.  Well, in that case, it's even a graver sin.  Even IF I believed that it was worthwhile to pursue some talks with the Modernists, that's not worth throwing the faithful under the bus.  You can just go to the Modernists and say, "Well, many of the faithful are troubled by the changes.  Take it of leave it.  Feel free to call of talks.  Maybe you shouldn't have messed around with the Rites for no particular reason other than to appease the Protestants."

Make no mistake that there are infiltrators and Modernist / Masonic / Communist / Jєωιѕн agents driving this agenda, which goes against all common sense, basic reason, and charity ... or else bishop / priests who have been compromised by Epstein operations.