Scarloc99, I recall your username from when I first discovered these forums. Peace! Glad we've both yet to feel the Mother's last embrace.
I think there's clues as to how it may have been done. I have some ideas I'll post later.
I was/will be so very thankful BS was able to complete the series. My first read through of those books, I was somewhat disappointed. I felt I could tell which parts of those books were RJ and which were BS. And this distraction? didn't allow me to enjoy the story as before, when the words were all RJ.
[I'm a Trekkie too and I so want to throw in a "Come. Share your Pain with Me." or whatever Spock's brother says in the 5th outing.]
I've never read anything else by BS that I can recall. And after a pause of a decade or more, I didn't recall noticing any difference in the writing. I noticed character changes, but those characters had it coming and it somehow all felt natural this time around.
I'm not looking for the difference anymore.
My take on Demandred's role...it was designed for him, by the Shadow and before the sealing, as a possible counter to the Light's champion. Same form of rule, unbroken, since the Breaking. Had Rand attempted their trials, he would have either failed or been corrupted somehow. Had Demandred gained the Angreal sooner, and come out of Shara as the "DragonSlayer", onto the Randland politic in a somewhat polite manner...very, very different story with maybe a not so happy ending