Are you doing A or B? I really don't think the skips are necessary as long as you're familiar with the map layout, item locations, and generally what objectives you need to do. The stretch between G1 and G2 was brutal, and I think I had to replay that three times. But then at that point I had memorized exactly what to do and how to handle specific situations. The good thing is that the only thing that changes is the adaptive difficulty. Enemy placement and item locations stay the same so I had gotten more familiar with each retry and planned out accordingly.
