That's the first I've heard of that. I thought that the wheels were rigidly affixed to modules 1, 3, and 5, and Module 1 and 2 have a Yaw link, Module 2 and 3 have a Yaw and Pitch link, and module 3-4-5 are the mirror of that, around the centreline of Module 3. This fully defines the position of any module tangent to the track that it is traveling on. Is that not the case? If any of the bogies can yaw relative to the module that it is affixed to, as you're suggesting, then the module position is undefined and it will not track correctly.