Hart is pretty much the same guy this season as he's been throughout his young career.
I think the Kuzma contract is a pretty good starting point for Hart. Kuz signed a 3 year 39 million dollar contract with a player option. The issue for Hart, though, is that Kuzma has: 1) shown exponentially more scoring potential than Hart, and 2) was a pivotal piece on a championship team the prior season.
Hart doesn't have nearly the leverage that Kuzma had, and he hasn't really been lighting the world on fire from 3, though he's been fine. I think the full MLE is kind of the perfect contract for Hart. He's better than guys like Moe Harkless who are getting 3-5 mil per year, but not quite on Kuzma's level in terms of production, potential, and leverage.