You should proxy cards that you dont have, cards that you own that are very expensive and youre trying to preserve, and ones that you intend for casual play or events that allows proxies
Theyll never know if the card you Foretold is an Instant, Creature or Sorcery, and anytime you ever hold priority to activate an ability at instant speed, theyll be quaking in their boots
for example, I didnt see any way to make a battle, double-faced card, or a traditional split card
It may also benefit from cards like Contagion Engine, Thrummingbird, and Karn's Bastion
I played these matches on a laptop with a Ryzen 5 3550h 4-cores, a Radeon RX 560X and 8GB RAM, with all the drivers updated
A Jace that lives past summoning sickness becomes doubly hard to kill, as he can flop to a planeswalker at instant speed a lot of the time