Not a professional, but:
In regards to handling, I wouldn't uncurl him at all. One, make sure you're not handling for a couple days after feeding - 72 hours is frequently touted - though you probably already know that, and then just let him be a ball. That's a defensive reaction, and means that he's scared. Forcing him out of it is likely to just scare him more. Just go read or watch television, let him be a ball in your hand or on your lap, and wait for him to get comfortable enough to unwrap himself when he's ready to be curious. Slow movements so he doesn't get startled, and not restraining his head or neck, since ball pythons are very protective of their heads. They seem to consider them particularly important to have!