Those are some hills, but on that second video with the New Holland I would have cut a backlash at the bottom. In other words instead of going to the bottom of the hill into the hole as we call them here, I would leave a patch at the bottom to be cut later and follow the contour of the hill better so one does not have to go down to the bottom and then pull up to the next ridge and turn on it at the same time spinning out in the process. This would keep the machine from pulling up hill on the steepest part of the hill alot. We have a steep hill not as long as that, but we always start at the middle going across the hill, turn down hill and come up the lowest part to the hill taking the next swath farther up the hill, but there is almost no climbing up the hill high up on the hillside, but close to the bottom. It is pretty much staight across the slope.
Those European combines are so Narrow, even the 1960's era IH combines we have had at least a 12 foot width. and the 1470 is about 20 ft wide at the wheels. I can't believe how much backing up is done going up those hills. Looks very dangerous with all that weight hanging so high in the air. My dad always liked the IH brakes on the hillside combines in the old days as they were on the wheel rather than on the transmission so if a drive line broke you still had brakes on the wheels. Especially important before Hydrostatic drive.