I'm not an expert on 3D printing, but it looks like this uses force sensing to make sure the effector velocity vector is nicely parallel to the position of the base plate. The effector is not exerting any force on an object. So it's velocity control not (the more demanding) force control.
Let me know if I have misunderstood what's happening here.
Sure, it's not yet there, but with the space of feasible is growing fast.