"Has anyone in the NRx movement (or outside it) summarized the arguments against the Enlightenment? Or its failings?"
Well, okay. Yes, this can be done.
The dumb, easy materialist summary is this: human happiness of no particular value; enlightenment "liberty" and constitutional government contravene property rights; "progress" is just atheist newspeak for Providence, and history is far more cyclical than progressive; tolerance is worse than intolerance; and fraternity is newspeak for blank-slate Egalitarianism.
The psychohistory summary is this: Enlightenment thinkers are Sophists. They're just lying. They're quite good at it, so it worked.
I grabbed the list of Enlightenment propositions from Wikipedia. Since they're Sophists they are regularly slippery about their alleged ideas. They don't want to be pinned down since a non-protean lie is much easier to debunk. However, turns out you can't buy good liars for $0 an hour. The list seems basically fine, although, as per the bad-liar archetype, La Wik's little digression about the start date of the Enlightenment is accidentally revealing. Fascism must always be ever newer, to disguise how old and stale it truly is.
The real story is that mortals regularly confuse the inside of Plato's cave for the outside and vice-versa. The underworld is the real world: the seeming lights are false, illusionary lights; the seeming darkness is true. The more abyssal, the more profound.
Enlightenment thinkers planned to turn up the alleged lights, and succeeded. They hate and fear Reality; they drag everyone else along with them into deep falsehood so that nobody accidentally reminds them of the intolerable Truth.
Anyway let's take the list point by point.
What makes human happiness valuable? The fact humans value it. Humans also value other things. Indeed humans often or even normally value other things more highly than happiness.
The "pursuit of happiness" line in the US constitution was originally something about defense of property. However, taxation is contrary to property rights, so a black government certainly can't have anything lionizing property rights.
And that's why Enlightenment thinkers want you to focus on happiness: so this nebulous, almost impossible-to-define concept can be used to distract you from vandalism, theft, battery, fraud. What you want is to satisfy profound values, not to be quieting the ephemeral impulses of your meat gundam.
Luckily for the Sophists, the meat is indeed distracting, and meanwhile you likely don't even know what your profound values are without hundreds of hours of contemplation.
Sophists looked at Plato's description of Democratic Man and was like, "Yes, let's order that one!"
In Reality, property rights give you control over your own life, and therefore constitute true liberty in any meaningful definition of the word. Enlightenment liberty is "voting" and including "a constitution" in the political formula. Enlightenment liberty is inherently anti-libertarian. They justify a black government which then meddles with your life; it both refuses to secure your property and regularly outlaws you securing your own property.
Enlightenment liberty does make the black government even more insecure. It is usurper-positive. The only thing worse than a black government is a paranoid, nervous black government. Allegedly it's okay for the black government to mess with your property if you're allowed to (symbolically, ultimately) mess with its property. Two wrongs make a right, according to Enlightenment thinkers.
In Reality, if you take two left turns you're heading directly backwards. Sinister.
If you have property you can dispose of that property so as to maximize your values. An Enlightenment government will only allow you to dispose of property in the (impossible) pursuit of "happiness."
In the state immediately preceding atheism, Providence was said to provide. Have faith in God. The Enlightenment was all like, "There's no evidence for spirituality! The divine is illogical!" So, now they have faith in Progress instead, which is the same thing except it manifests the anti-logic they accuse theologians of using. "The arc of history bends always toward more Progress!" "Why? Who causes this?" "Ummm...hey look a squirrel!"
First, it's about Fascism. Faith in something other than the black Sophist government can't be allowed. Their government is weak and can't handle the slightest competition for loyalty.
Second, it's about justifying the Enlightenment on materialist grounds. Technological discovery is claimed to follow from and only from Enlightenment philosophy. Technology makes you Happy, doesn't it? Obviously there is nothing valuable except Happiness, therefore you must support Enlightenment Sophists no matter how disgusting they may seem.
I would also like to note a disturbing faith in permanence. Those socialized under Enlightenment values believe progress is nearly irreversible, although if it is reversed - if Hortlor gets into power - the stagnant state could also be nigh-permanent. When they think of a thousand-year empire of a tyrant squelching the people, constantly silencing the endless cry for progress, they think this is even vaguely physically plausible.
In Reality, Progress is Regress.
If new technology is discovered or researched, it is despite the Enlightenment, not because of it.
Tolerance is particularly Sophisticated. What tolerance allegedly is changes based on whatever serves the Sophist at that particular moment. Kto kogo.
Tolerance is, again, contrary to property rights. Tolerance is about allowing
events or persons on your property that you don't want to allow. It is
about suppressing your own values in favour of the Sophist's values.
Most often it's about the fact that Sophists need gulls. If nobody listens to their specious arguments, they are powerless. However, gulls are rude, criminal, low class, clinically insane, and/or foreign. Hence, you must tolerate their voting blocs.
In theory tolerance is about the fact a sacred cow is a falsehood you're not supposed to question. If you gore a sacred cow everyone gets upset. However, a true truth-seeker must tolerate the goring of sacred cows. In Reality the Sophist is the first one to set up sacred cows and is only interested in goring the sacred cows of outsiders. They are radically intolerant. In Reality, stripped of all pretenses, Enlightenment "tolerance" is nothing but a base scam.
There is a valid form of tolerance in the vicinity, but without Catholic Universalism of the Enlightenment, nobody would think to be intolerant in that way in the first place.
(Namely, mores are local and thus morality is local. Absent Catholicism it won't occur to you to condemn the mores of distant strangers as inherently immoral. Indeed to someone socialized outside the Enlightenment, it would be stranger for distant peoples to have the same mores as you do. Freaky.)
Fraternity is even more nebulous than tolerance. We have to impute something to it because the Sophists won't stop to talk about it at all.
I go with [brotherhood of humanity].
Catholic Universalism and blank-slate Egalitarianism. Everyone is identical; if they don't look identical it's because of False Consciousness.
Since everyone is identical, we must all have the same interests and values. (I.e. Happiness.) Anyone who seems to have different values or interests must be malicious (traumatized in childhood or whatever) or insane. Confused, at best. We must bring the Gospel to the unEnlightened heathens! The Gospel of Voting and Tolerance and being Happy through not owning anything (because Communism is very Sophist and the black government wants to arrogate all property to itself)!
I don't even feel the need to debunk this. No wonder the Sophists refuse to talk about it explicitly. Nobody can spin that into anything even vaguely plausible.
Wikipedia also mentions the pursuit of knowledge through logical reason and experimental evidence. When Enlightenment thinkers say this, they're just lying.
It's mainly a sugar coating to make the bitter blue pill go down smooth. Secondarily it was happening anyway, they didn't yet know how to suppress it, so they confiscated credit and successfully twisted the process towards their own destructive ends.
"The central doctrines of the Enlightenment were individual liberty and religious tolerance, in opposition to an absolute monarchy and the fixed dogmas of the Church."
They're just lying.
Sophists realized that gulls could be fooled by a thin veneer. They like the iron fist; they merely replace the velvet glove with an illusionary glove. Every American voter is a slave. However, you're allowed to choose your own job, meaning prima facie it doesn't feel like being a slave. And that is quite sufficient.
Sophists being Sophists, this veneer has become incredibly sophisticated. However, it remains nothing but a veneer. In the long run you realize something's wrong and become...unHappy. And then take fentanyl until you overdose and die.
Sophists tell their gulls they can reason through theology themselves. They can't. Gulls who attempt logic end up at materialism, because they're lazy and undisciplined. (But everyone is identical; if a gull can't disprove materialism, nobody can disprove materialism. At least, according to kto kogo.) Materialism is easy; Truth is more difficult. Sophists use this to discredit competing religions.
Pre-Enlightenment governments aspired to tyranny. Post-Enlightenment governments aspire to tyranny. Sophists found they could put up a layer of security over their tyrannies by pretending to oppose tyranny. The Enlightenment was an advancement in black government design, nothing more, nothing less.
Sophists are smart, so it worked right away. Indeed, in retrospect, it appears that dumb, gullible peasants like tyranny. Non-tyranny doesn't make them at all Happy.