I am generally a fan of Charm and Command cycles, as I think they allow for interesting gameplay, since you can change their function in the context of a given game as opposed to it being rigid in what it always does
Paired with Spelunking, this allows for some incredible mana bursts, and several game-ending combos
If you roll more than one die at a time, however, that does count as multiple die rolls
One of the things a higher-complexity set could allow is the creation of higher-complexity mechanics
Commander precon card) Experimental Lab at 3G utilizes manifest dread, but with the addition of two +1/+1 and a trample counter, turning the manifested card into an immediate 4/4 trampler, creating an instant value-per-value threat