I am an engineer among other things, though I've never designed a bike. There is no doubt the truss system is as strong or stronger for the weight, but an isolated blow to one of the interior members of a truss would do a lot of damage to the overall capacity depending on whether that particular member was designed for tension or compression. In a dynamic system such as a bike frame, most of the members probably experience both T and C. In any case, my fear would be that should any of those small members go out of plane and become plastically deformed in transit or even from an accident, it could cause the whole frame to buckle depending on what kind of factor of safety is embedded in the design. It is an interesting concept, and fortunately bikes don't tend to undergo extreme loading compared to capacity until you really try to dial in the weight. I'm sure if you promised Moulton you wouldn't gain any weight, they would design a bike with only 5 lbs extra capacity to get the weight down as much as possible. With finite element analysis programs available today it could be done very quickly. The frame would be very fragile and deflection would become an issue if they went too small, but you could still get considerable moment capacity out of space frame of 9 gauge wire.