Not really. They would have told her nothing very useful, let alone reliable, without putting them to the question, and information you get from people you torture is always very hard to trust. The DF/BA would have given her any drivel they thought she wanted to hear to stop torturing them. She might have gotten a few gems lost in a big pile of dross.

Torture is illegal in Andor, even for the Queen.

Deceiving the BA that she was Forsaken was the most clever mean, and she got truths out of them. Elayne should just have thought about it much sooner, then deal with the women immediately. She should never have held them prisoners so long. All her experience with BA told her this would end badly, perhaps very badly.

Other than her clever deception, Elayne should have done exactly what Egwene has done: put them all to death without any more ceremony. Perhaps like Egwene she shouldn't even have bothered with putting them to the question. Elayne learned nothing Verin had not already told Mat, or written to him.

That these women were BA wasn't in question. It was already proven beyond reasonable doubt, an Amyrlin had declared these women were BA and in fact Elayne/Nynaeve were originally given carte blanche from Siuan to deal with them as they saw fit. Siuan never asked any of them to bring the BA alive to the Tower (Moiraine made that decision), she gave them a writ that even let them kill them on sight if needed, all under her authority. That authority no longer applied (and never did for Elayne, actually) but Elayne could eventually testify that all these women have broken at least one bound Oath, and that's evidence enough. Not one Sitter would have challenged that they were BA. They would have grumbled about not being able to interrogate them, but Elayne could tell them how much good that did with Ispan, and how many people Careane killed.

As long as Elayne proceeded secretely, pretending the prisoners had been sent to TV and no one in Andor but the few involved sworn to secrecy knew the Queen put AS to death, Egwene would have been all too happy to cover it all up. Even if the Hall learned, she would have gotten away with a penance at best. After the BA purge, no even with that. No more than the BA hunters did.