Ad Nauseam combo has long been a fringe archetype of Modern, and these two lists present new directions to take the deck.
The first list is rather simple. It has Spoils of the Vault, which is quickly becoming stock. All you really need to do differently is play a second win condition to make the odds of removing all your win conditions much lower. The real technology comes out of the sideboard. Fighting through the Jund and Abzan decks can be difficult, but Grave Titan makes that simple. Not only do they have to fight your combo, but they also need to keep in some creature removal, lest they risk losing to the jolly black giant.
The second list is where things really get interesting. Everflowing Chalice appeared in some Ad Nauseam lists, but it never really stuck. Perhaps they just weren't trying hard enough? This list eschews the Pentad Prisms and Lotus Blooms in order to turn on Mox Opal, and Everflowing Chalice is a big part of that. Darksteel Citadel and Mishra's Bauble round out the artifact suite. Mox Opal not only speeds up the combo but allows you to cut the Simian Spirit Guides for actual mana accelerants. Once you combo off and draw your deck, you can produce red mana with the Mox Opals.
It seem weird, but the artifact-based list doesn't actually play any cantrips. Instead, it relies almost entirely on Temples to find what it needs. That may seem odd, but you end up looking at a lot of cards before you die. Plus, turning on metalcraft isn't easy, so you don't have many slots left. I could imagine not needing eight Pacts and four Engineered Explosives maindeck, but it does give you a bunch of ways to prevent yourself from dying while you hope to draw into your combo. I'm not sure which way is better.
Regardless, both of these lists show there's more to this archetype. Putting together a two-card combo might seem simple, but there's more than one way to get to where you want to go.