I wouldn't. First off, I wouldn't care. I've made bows with a lot more difference between the limbs than that. What matters is that the limb strengths are balanced relative to your holds at full draw. Not what it looks like at brace or unbraced.
Second, I wouldn't steam a dried piece. If I wanted to move it 5/8, I'd hit it with the heat gun. But like I said, I wouldn't worry about it.