Drop stitch technology can be useful and strong enough to realize full double discs (for more rigidity) or crowns (if possible for saving material) comprising tracks for the belts settled between the respective discs or crowns. They need to be under fairly high pressure (as for drop stitch paddles) to support the tension of the belts , while the balloon as a whole remains at barely above normal pressure.
A part from the double discs surrounding the balloon, the envelope is a simple ripstop envelope, like that of a hot-air balloon, which is what this balloon ends up being with the electric heater to gain few degrees.