I remain curious, however, as to how they managed to have it work.
One could argue: why 12 MOPs? Why so little damage visible? What proof do we have anything actually occurred? Or even, doesn't Gen. Caine's expose come as "justification after the fact"?
It is true that 12 MOPs can sound like overkill. Prior to the attack we were told "a" MOP could be used to take out some of the facilities, especially Fordow. Raising concerns and questions as to the actual efficiency of such a device and its relevancy for the task at hand.
Though the discussion prior to the act brought forth pros and cons, it was nothing but throwing various more or less well argued speculations.
Then the strike occurred, and with it came the first pictures of the outcome showing slates of concrete ripped and tossed away. But also came to light the fact not "a" MOP but several MOPs were used simultaneously on a single target.
Prior to any official statements regarding the details of the operation, anybody looking at the pictures could come to the conclusion that 6 holes were visible. From this it was deduced "6 MOPs have been used". Various claims were made giving credence to that line of thinking, with numbers varying around the purported "6".
Then came further official statements culminating with the press briefing given by Gen. Caine stating that not 6 but 12 (!) MOPs had been dropped on Fordow. (that would require... about 24 Taurus?

)
MOPs and similar ordinances are rarely used. In fact they are exceptionally used, with the latest instance being a strike conducted in Afghanistan against high-ranking members of Al-Qaeda, and before that I would say a GBU72 in Yemen and the GBU28 during Desert Storm.
So, 12, in one run, can sound overkill to some extent.
However, one has to keep in mind that, to kill Nasrallah, Israel dropped about 80 bombs (80 according to NYT, more than 80 according to Reuters and AP), with Al-Jazeera reporting up to 10 GBU72. Subsequent reportings mention the use of BLU-109.
Anyway, the point is though it may look like overkill, if you want a target gone you hit it until it is, indeed, gone.
Historical operations aimed at destroying crucial enemy elements involved such "extravagant" use of force, especially during WW2 with the Grand Slam, Tall Boys and the like. For instance during Operation Catechism, that led to the sinking of the Tirpiz, 29 Tall Boys got dropped; though, yes, accuracy, at the time, was very hard to achieve and only 2 scored a direct hit and another one a near miss.
Or even the Dambusters, though, again, the redundancy is more likely linked to the fact at least one hit needed to be scored rather than several, the chances for the bombers to reach their target being relatively small.
So, is the use of 12 MOPs on one target too much, especially since the US isn't facing the same challenges the RAF did during WW2?
One could say yes, as in "if you need 12 of these to reach your goal it means your system isn't really that good".
Which could be considered as a fair take.
But another one can also be: the system is that good, we can use it and we want to make sure we won't have to conduct another run in the future.
According to Gen. Caine, that's what it was. One to pop the lid off, 5 to hit the target proper and one last one just to make sure.
BDA wise, it is true that, for the public, it is relatively poor with the secondary effect of being a kill-joy.
What can also raise eyebrows it the number of entry-points. We can only see 6 total.
If what Gen. Caine says is actual, that would mean the GBU are accurate enough to thread needles, and it feels like, even today, we aren't ready for such systems to hit the very same spot twice. Let alone being able to consistently repeat that threading that many times.
edit:
Another illustrative explanation, furthering Gen. Caines press brief.
Also explaining the gray dust.
Somehow some explanation for that gray-color was "the fire raging underground had the stone turn blue". Which... I suppose could happen? However, we haven't seen, nor aren't we seeing, any smoke coming out of the site.
Even coal-mine fires produce smoke.
And considering the explosive power of the 12 MOPs, surely there would have been fault lines created in the overall mountainous structure allowing for dust and smoke to navigate and exit.
I suppose, again, such emanations would carry a modicum amount of radioactive isotopes that would have likely been picked up by Sniffers.