Not that I recall.
Unless I'm forgetting something you've raised two basic counter points.
1) Controlling who has access, which is technically possible for some of them but so difficult the people designing them didn't bother. Just locking them up was already a trial.
Seal of Eight Divinities worked perfectly well to distinguish between Autochtonia and Creation, and prevent exaltations from selecting mortals inside it. I am not sure, but I think humans surviving inside Malfeas also couldn't exalt unless the free exaltation also happened to be inside Malfeas.
Distance and perfect effects are capable of limiting the selection pools of exaltations. From there, providing an exaltation with a pool of acceptable candidates within a designated area has at least a non-zero chance of success.
2) Somehow getting in contact with them as they're chosen all over the world and getting them to sign up with us. Which doesn't account for the fact that these are going to be people with their own motives and beliefs that we have no reason to believe would be in alignment with ours.
Assuming it's just Molly acting with no prep? Use the vault itself as a focus to find the locations of all Exalts. Use RVD to travel from one exaltation site to the other, using Essence-dissecting stare to find exalts within the closest five miles, and using local areas as foci (scene foci fade after a year and a day) to further narrow down the search. This is the worst case scenario. A better case scenario is one where Molly and allied forces have forces have identified likely candidates via magical astrology (should work at least for sidereal potentials), have agents in place in all major and minor cities, have called in favors from Winter, Summer, Odin, White Court, Roman Catholic Church, the Library of Congress, Archive (who gets access to all cameras with a recording device everywhere in the world in real time) and other factions, and the agents of said factions will be with the newly exalted within an hour of exaltation, using carefully prepared introductions to explain what the hell is going on.
Suppose we get a Lunar with a grudge, more interested in killing fey nobles than in any consequences of their actions. How about a day caste who thinks the masquerade should come down, regardless of the casualties involved in just doing it? Betting everything on being able to talk other exalts down from their own motives is not a good plan.
Assuming that an Essence 5 social-specked Molly with social-boosting splendors crafted specifically for the occasion, with fortune path boosts, cannot talk down an essence 1 newly exalted (because they have perfect defense and intimacy X: all-consuming hate), and cannot wear them down, and cannot imprison them (it's quite possible to imprison an exalt for a prolonged period of time) and then talk them down, and they are an active and uncompromising danger to reality? Molly kills them. Or Mab kills them. After some time a group of their elder exalted peers kills them.
We don't need to perfectly catch every exalt. We need to have a plurality of exalts on out side for the system to self-stabilize into a situation where our position is leading.
No we aren't, not in this respect at least.
The age of legends didn't really have any much in the way of cultural or religious divides, and the open warfare consumed so much attention there wasn't time for serious political knife fighting for the most part.
After it was over the concentration of power kept things running, but there's a reason that the dragon blooded kept hunting Solars down instead of trying to salvage them.
The reason dragonblooded kept hunting solars down was state-enforced religious dogma. Age of Legends had Great Curse, and the embodiment of all virtue hopelessly addicted to games of divinity.
Which is why the UN has solved all global conflicts right?
People aren't 100% reasonable all of the time, and even when they are trying to be it doesn't stop conflicts of interest.
I'm also skeptical of the idea that we could run all over the planet, crossing variably hostile territory, to pick up every single exalt out there and convince them to all cooperate despite having nothing in common but power. Especially once other powers start making offers.
But did UN make things worse? A solution doesn't have to be perfect to be better than doing nothing or maintaining a status quo.
Most warlocks are minor talents who are fairly weak. They can do nasty stuff, but for the majority of history they weren't really able to become more than a local problem most of the time.
Proper wizards are dangerous, but they take a relatively long time to grow into that power fully and need a lot of training to really get up there. They're also vulnerable to the basic human condition, as Butcher notes in his WoG.
Also worth noting that people like Molly and Dresden are wizard heavyweight champions. Summoning evil stuff is on the table for them, but the average wizard isn't going to be animating armies of zombies easily.
They're an accounted for part of the world that has a long spin up time and have to put a lot more work into breaking the rules.
A wizard can't really replicate the crown of eyes, launch high grade global range curses on nearly arbitrary numbers with zero warning, or permanently kill true immortals without playing the special circumstances game.
If I understand correctly, summoning demons (not outsiders) is relatively easy. And, again, self-reinforcing loops.
The white council isn't a good example for what you want anyway. Its core purpose is to limit the power of wizards over the mortal world, something that was important to keeping it together in the first place. It's noted in a WoG that there's a lot of stuff they couldn't get involved with in the first place, because having members from all over the world meant that poking things would inevitably cause internal conflict. We'd have the same problem.
So, why wouldn't this model work for exalts? It worked for wizards, mostly. A variant of the same model, where exalted society keeps each other out of politics, limiting themselves to "general good" things, like developing clean energy (but not pushing it), protecting reality from monsters, etc, is a solution. It's not a "new deliberative" solution, but it's better than status quo.
It wouldn't work as a direct copy and paste of White Council, but as an interim solution it's viable.
EDIT: More detailed threat mitigation plans can be developed, and I acknowledge that adding a new factor to a stable ecosystem increases risks of systemic collapse while a new equilibrium stabilizes.
