Given the prevalence of Lightning Bolt, Unholy Heat, and Fatal Push, Humans is going to need something extra at the top to grind with the various flavors of RBx Lurrus decks
Dragon's Claws seen tournament sideboards, and Kraken's Eye is fantastic with mono-blue Eye of the Stormall cards off it are cast, making everyone play blue if you like
Effects that increase or reduce the activation cost of Heirloom Epic's ability apply before costs are paid and will increase or decrease the total number of creatures you can tap
Trying to lower my count
Overall, Turbo Gears looks like the most engaging drop to me due to its high concentration of Commander staples and some already-pricey cards that ought to hold their value
Jeskai does give us access to a number of untap effects, so even a simple Freed from the Real on Liberty Prime would help mitigate its costly energy generation effect, but we were probably planning to do that anyways in Dr