I don't think scaling this up is a question of inertia it is more a question of weither a material exists that can be used in those flexural joints with much higher loads.

This is a material science question. A material may exist that has the right combination of flex, strength and lets also not forget durability. I am a mechanical engineer and crack propagation and cycle fatigue would be a major concern for a joint like that at large loads. There are all kinds of amazing tricks material scientists know how to play to combat these types of problem.

I think this could be scaled up if material to make those flexure joints exist.