What's the point of the scratch pad? Isn't the same data already in the context? Or does it help because contexts are lossy and bias towards the start and end?

Similar question with the to-do list. Do they actually help task completion? Is there any research on that? I think they're less helpful with more recent models, but maybe they still help with smaller ones?

The system prompt asking it to make a plan before starting work does sound helpful though. (Of course it would also be great to see numbers there :)