These days we've been trying to design a small mechanism that allows the 4 hooks to rotate with the full face of the module. The idea is that, when mechanically connected, the modules can change their relative position (for example, to change from a 2D worm structure to a 3D snake movement).
This is the first test, with the 4 hooks on the rotating plate:
Having rotating faces at both ends of the modules, we could use them as wheels to move on flat surfaces.
Still a looooot of work to do, we will keep working!