I... don't think being a Start character defines whether a positive or negative state of Production is that character's drive. That being said, the difference between negative Production and positive Reduction is this. Negative Production does not create new options, which causes problems. (For example, you could think of it as an illustrator for a company who keeps using the same general types of images in their work.) Positive Reduction, on the other hand, actively removes options. (For our illustrator example, they'd be a new illustrator who thinks the company's current website is too kitschy and avant-garde, so they want to revert it to the tried-and-true basics that have been used for decades.)
Same principle behind the difference between Production and Potentiality. Production is, essentially, creating new potentials; Potentiality is working with what already exists. You ever have one of those milk cartons that you have to fold to open? Potentiality is using either fold to open it; Production is turning it upside-down and stabbing the straw through the bottom.