I'm totally undecided if Singing will play a role at SG or if it allowed RJ to turn the world into a living hell during the LB (one in which humanity wouldn't survive long even if it wins against the DO) as it provides a way to "heal the land" afterward. I don't think Ogier Singing is that important. Seed Singing required Nym, but my hunch is that Nym were created so that mixed gender circles of AS aren't required to focus the Singing (in other words, AS can do the role of Nym in the process).

The people are already starving, and the few resources left are roting. Rand can affect this, but Rand may not remain around post-TG, or at least his new powers as Champion may not remain (I doubt the point is for Rand to become a living God, and it's what would happen with his current powers. He's rather like a living message/demonstration that the Creator has not abandonned humanity, that his will acts through his Champion. That's not something I expect to remain post-TG, even if Rand were to survive). The LB is set to be fought over the summer (so, basically no agriculture at all this year), which means after the victory, the next winter might finish what Shai'tan didn't manage to do. It's also fairly plausible that the world will face epidemics (they've already begun). I wonder if this isn't the final purpose of the weather ter'angreal and Singing, Healers etc. - to be used to save humanity in the post TG months. What could force the AS and other channellers to fully return to service to humanity? It could be that survival of humanity itself won't leave them a choice, that the world will need them and the Aiel. To engage her alliance of channellers in that task fully might be Egwene's big final contribution, and this would completely alter the way people perceive the channellers and Aiel.

LTT's solution shielded the Bore, sealing it out of reality. It required the OP and touching the DO directly with it to place the seals. That's not the solution, as we know.

It sounds to me like a possible avenue would be to force Shai'tan to release his grip on Creation long enough to heal "the weakness" without having to touch Shai'tan. It would be back, more or less, to the pre-drilling situation. The only thing I can think of that might make Shai'tan temporarily "retreat" is the taint of SL. If the "three becoming one" refer as I think to Rand-Mat-Perrin, that would be like having a mega-ta'veren and we might have to look no further for how the weakness will be removed (by the Wheel or even the Creator acting through the three. Rand used to be a counterpart to Moridin, but post-epiphany Rand seems to be more and more like a counterpart to Shadar Haran.. it could be that what's expected of Rand and humanity is to temporarily force Shai'tan out of Creation, that the "mending of the pattern" itself will then be effected by its Creator itself, working through the three ta'veren. After all, LTT judged himself harshly, balmed his own arrogance to have thought he could mend what the Creator himself had done. Perhaps it's right this requires "godly powers" beyond the reach of humans, and Rand has to deal with what prevents the Creator from mending the weakness created by men with the Bore: Shai'tan's grip on Creation. That the Pattern will "heal itself" or that the Creator will then act, would be a big leap of faith (and Fel's "order and belief" may be a hint that it's heading this way). Before the epiphany, LTT thought the Creator didn't care/had abandonned them to their own devices. I'm thinking the conditions in which the Creator will want to or be able to act just aren't met. Early in "AMOL" (Jordan's original 1 book plan, I mean) we learn that Shai'tan is the True Power. Everything in the Pattern, the Pattern itself, is the One Power. It seems to follow that the Creator "body"/energy is thus Creation itself. This could mean that by his own choice to make Creation, the Creator has forsaken the power to interfere with it, as all his energy is invested in it. So to be able to "mend" the Bore, which might require knowledge/skills only the Creator have, he might need the three ta'veren "as one" to focus humanity. Rand would in effect be the vessel through which the Creator can make the alterations/reparations to remove the Bore, but this can't be done while Shai'tan grips it.

It could well be that Singing plays a role in the mending. I get the feeling that Singing is a "passive" way of using the One Power, and that what can be achieved is greatly affected by the nature/actions of those who do Sing (unlike weaves, that directly affect the Pattern following the will of the channeler, I think Singing simply "betters the Pattern", so to speak. Creates near ideal conditions for the Wheel to reshape things to an extent). Aiel warriors still sing, battle songs and mourning songs only, and though Singing is in their genes, this does nothing at all. I think it may have surfaced when the Da'shain philosophy reached a certain stage of purity, and in turn have driven them to even more extremist behaviors/beliefs.