There is a cross strap between the shoulder straps high on the chest and when this is buckled, the tripod weight is then partially born on the backpack support straps. As a mountaineer , wt has been a primary concern of mine for a while. Superb negatives , light , protectable- under parka . I fabricated a filter adapter and use 46 mm accessories with good results. The downside is no interchangeable lenses, which can be faked a bit on the telephoto end by enlarging a small part of the neg.
Wide angle is more problematic.
But the mutars are expensive and hard to find. But they are out there. BTW, Rollie made a 1.5x Mutar as well. I have seen two different types of bodies and prisms. First the bodies.