There are no specific economy/inkwell cards in the deckinstead, any cards with the inkwell symbol on the top left (a fractal hexagon fill of the ink cost) can be put into the inkwell
While Sofia will always be a decent piece of removal, especially considering Commanders are Legendary, you can definitely get a similar effect for less mana, making Sofia kind of clunky in the long run
The fact that you still get activated ability goodness when its on the opposing team is especially nice flavor
It's a temporary mana maker, and I prefer permanent ones like land rampers in spell form like Cultivate, Rampant Growth or Explosive Vegetation or in dork form like Sakura-Tribe Elder, Wood Elves or Solem Simulacrum to ramp the harder to answer lands
Sorry, still no consideration to Sealed, Draft, or casual this time around