I can confirm that when the Herbalaire stops producing vapor, the nugget is spent. I ground one up and put it in the Herbalizer and got nothing.
So I've been using nuggets for a while now in everything, and I like it in the Evo best. It thoroughly cooks it and, best of all, it starts hitting hard on the second or third pull. Most vapes don't hit hard at all until I crumble. With the Evo, I don't crumble until the very end, and then I get a few more hits until the abv comes out dark coffee brown.