If Affinity is built to maximize Heist, then by definition you make Heist better, but I'm not sure you're making the deck better
You just need ways to maximize your hand size for beats, so that'll be things like Reliquary Tower and card draw like Fact or Fiction and Tidings
Monored is one of the most popular color identities in Commander, with its focus on Dragons, Goblins, and all-out attack attracting many Magic: The Gathering players
Put in a bunch of other stuff like a cycling land or an enchantment that sacced for a land (or Steve Sakura-Tribe Elder) and such, and then use the entomb effect to get the big thing and recur it
Back in the day, people played Ice Age/Alliances sealed deck, and had to use the worst cards imaginable to win games
So, Grand Summoner turns loss into momentum, feeding on sacrifice