Keep in mind that the Primordials may have had infinite power in their own ways, but were limited in far more ways than even mortals. The Primordials could not act beyond their themes, limits and tyrannies. The Act of Exaltation requires a human to become a Hero, to go beyond their limits and position whilst acting in a manner that is 'Virtuous'. The act of defying the Primordials is inherently Heroic, and by simple virtue of the fact that the Primordials saw it as their place and nature to dominate humans meant that they would have naturally winnowed out a great majority of those who would have had the capability. It would have been a case of going "Oh, I've heard chickens can fly? Okay, here's my coop full of chickens with clipped wings. Let's see if they can fly. Hmm, doesn't look like it."
That's not to say it would have been tautologically impossible-except for the Ebon Dragon, whose nature is utterly anathema to all concept of Heroism. The only Exaltations that occured around TED would have been Heroes rising up specifically to face him.
They could rebuild them once they had them locked down, generate curses that exploited their nature to force malicious updates, and depending on the edition figured out how to make their own.
My point is not that they're impossible to manipulate in all ways, but that it should always be incredibly difficult and some shouldn't be allowed without something genuinely novel.
Ancient Sorcery and Splendors are aping the power of the primordials, fate bending is operating a system they built and could similarly command. They were alien, but alien doesn't mean stupid; by the time acausal WMDs are getting deployed it can be assumed that all "one neat trick" options have been explored.
Which is why I'm using the great curse as a standard. The solar sparks were not captured or redirected until after someone with the authority to do so turned them off and put them in a box, despite all the effort that we can see and infer went into going after them.
We're an outside power, so to follow this to a reasonable conclusion I see a couple hypothetical ways to influence but not personally select exalted candidates:
1) Work out a great curse tier act of techno-sorcerous engineering nobody from the primordials all the way down the ages to now could possibly have ever accomplished that manipulates them once deployed.
2) Emulate the Yozi in full by learning enough deep exalted lore to rebuild them in our image and adding the chains that let them pull the plug on undesirable candidates.
Fate manipulation and isolated dimensional regions are kiddy shit in comparison to what the primordials could do. By default they had isolate pocket dimensions
as organs. The question of what happens if an exalt dies in a sapient and hostile alternate reality which wants to steal or destroy the spark is one that had to be answered as a basic part of their design.
1) No sidereals to identify and oppose our Fate manipulation
2) Either no Lytek equivalent, or (if we can make one) Lytek equivalent loyal to us, unlike the Primordial War, where Lytek was a part of rebellion (and also a god Primrodials didn't know about until the start of rebellion).
3) No Autochton to oppose us
4) No ongoing Primordial War with an opposed Exalted Host messing up any prep and setup required for a sure way manipulation. Opposition got a say, after all. And exalted spies and assassins were good enough to murder Fetich Souls of Primordials at the start of the war.
5) Reality, and Destiny, are easier to manipulate in this latter age.
Like, let's look at this mechanically. Destiny Background lets you, to quote
One use of VEE can give a person 1 dot in a background. You cannot use VEE on a person more than once per year (or unless you trick reality into believing that a year and a day have passed). I am fairly sure that exaltation is a legendary enough success that you need a legendary Destiny success to get it. Ie 5+ successes.
If we go by a very free interpretation of splendor mechanic, you can get up to +3 automatic successes by stacking 3 Invincible Assertions on top of each other. That would be a 5 dot splendor, by the way. Ie you'd need to kill at least three gods to power its creation normally in WoD (2 in this quest before we got the Forge). And it's likely to be destroyed after being used. This still leaves you one success short. So, you need to use 2 VEEs on a single person. And equip them with a 5 dot splendor. This gives the target 2 dice of Destiny + 3 automatic successes.
That hard enough for you? I full expect to have to use fae court favors, probably from both courts, to make this work. And, given that Mothers are mainlining surviving Maidens in this crossover, this seems appropriate enough.
The sparks of exaltation had to be designed to enter a hostile jotun body to assault the supreme god of local reality where fate is by no means ensured to be the dominant force.
The Maidens couldn't oppose the primordials and I don't see E1 sidereals stopping them from picking up a shiny object if they wanted it under those conditions either.
The scale I'm using is the Yozi's desecration of the solar sparks and the great curse, so stuff like this doesn't move the needle from my perspective.
