I'm just now reading the whole Emma/n2n/playbill debate, and in my playbill from September 18th, Emma Hunton is listed with Mackenzie Mauzy. Adam Kantor is also listed as a Henry u/s. I remember this weekend because the board had the two additional understudies listed and it was more full than usual.
That said, I don't think anyone can trump Meghann in the role. I was not a fan of Emma's inconsistent performance and actually preferred Mackenzie Mauzy's rather unrehearsed portrayal of Natalie (I think I saw her second show) to Emma. She was MUCH stronger toward the end of her run, but I will never be able to shake the first few times I saw her from my mind - it did not sit well with me and I didn't like it at all.
Larkin Bogan is a better and much more likable Woof than Matt DeAngelis in Hair.
She's not an understudy, but Marni Raab performs twice a week in Phantom and vocally, she's better than anyone else I've ever heard in the role, ever.
"I will not cease from mental fight, nor shall my sword sleep in my hand: Till we have built Jerusalem in England's green and pleasant land."