[Balero]

I suppose you have an incomplete model where you haven't thought of and understood all of the corner cases.

I don't think you ever 'finish' a refactor! But you get to be able to deal with your everyday without bumping into conflicting information that causes you to have to refactor every day.

I think a partial refactor would be bad because you're working on an inconsistent model, and if it's wildly inconsistent then it can cause you issues, and might not be a complete model.

For example, imagine you just learned that sugar is bad for you! But thats the sum of your new dietary knowledge. So you start going for fatty foods with lots of preservatives. This isn't going to be any better for you. And you'll have to 'refactor' when someone points out your new diet is still bad for you.