The MultiBodyEnd component add zero force and torque to a FlangeWithBearing component.
But why is this needed? Everything seems to work fine even without MultiBodyEnd .

Moreover, when we connect frames or flanges it's automatically true that this connectors does not add any force or torque.
They simply say:
sum(f) = 0; (flow variable)
r_0 is equal for all connected objects (potential variable)
Thus, why FlangeWithBearing (that is still a connector) may behave differently? isn't it a simple merge of a frame and a flange?
Why we need to stress that it is not adding any force and/or torque?