I could definitely see changing the third Jace, the Mind Sculptor for a Keranos, God of Storms, as this one cant be killed by Lightning Bolt and a later drawn Red Elemental Blast
This card does spread that "mill damage" to every player, which can be really potent in itself, but turning off some of those win conditions to mill more feels a bit durdle-y to me
The relevant MTG cards here are Ghalta and Mavren, and Etali Primal Conqueror
unlike those cards, both Channeler Initiate and Traverse the Ulvenwald turn into real cards in the late-game
Unlike Izzet, Spacecrafts actually have a better home in Dimir control, particularly if you pick up Susurian Dirgecraft, which comes with built-in removal