I really don't think that's the flaw. I think the flaw is that LTT put band-aids over the Bore instead of truly repairing it. Seals made from both sides of the Power would have had the same problem - the Bore would still exist, it would just be patched. For the Wheel to come full circle, the Bore has to cease to exist at some point and I think the end of the Third Age is that point.

If there was anything useful from LTT's rantings about Latra Posae's refusal to help LTT with his plan, then IMO it is that Rand needs to work with women channelers to achieve his ends instead of things being like they were between the men and women in the AoL. Not all of them (he doesn't need the whole Tower following him and doesn't need to bend knee to them either), but he does need their help. The thing is, he has it in the form of Cadsuane, Nynaeve, Alivia, and the Aes Sedai who have sworn to him. They are the ones who can help him, not LTT. LTT likely has no idea why the seals didn't work properly and is too insane to be of much use in figuring it out. What Fel told Rand is of far more use but he needs to get the input of others to help him figure out the riddle instead of asking an insane man for guidance.

The more I think about LTT and Latra Posae, the more I see a reflection of the Rand/Egwene relationship - the two of them were apparently adversaries and thought the other one was an arrogant jerk. They each thought they knew best and it was LTT who finally relented and went with LP's plan, but when Latra's plan failed because of the CK being taken by Forsaken, she still refused to compromise. LTT, at that point, was convinced his way was the only way (as LP believed hers was the only way) and since he believed time was running out he moved ahead with no help from the women because LP convinced all the women to refuse to help him.

Thankfully, this time the Pattern has interfered and given the Dragon some female channelers who want to help him (Caddy, Nyn, Alivia, etc.) and who will help him even if this age's Latra Posae (Egwene) doesn't like it because she thinks she should be dictating all of his actions. It would be in Rand's best interest to accept help from the women he has with him and forget Egwene. Let her deal with her own mess.

As for sealing the Bore, he needs to forget the seals (I think him trying to do a repeat of LTT's plan with both sides of the Power would end in complete and utter disaster) and find the meaning behind Fel's words. When he thinks to himself that he needs to get to TG before there's nothing left of him to kill, he's right. He needs to forget trying to bring peace to the world (peace he admits won't hold because no one seems to want it) and get on with what he needs to do. He has what he needs in the Aes Sedai with him, Alivia, the Asha'man, Mat's army, and Bashere and his army. Everyone else can either follow his lead, and stop bickering like a bunch of children, or they can die at the hands of the Shadow.