Personally the best example i've seen is the new little spinner (FBS version) with a link inside the shaft at the centre of the robot as you have suggested in the first post. But if all the rules regarding locking pins are also followed then even if the link is not done by this method it can still pass tech check. The robot will be armed and disarmed with the bar locked to the chassis by whatever method you choose usually a bar through the chassis. So when the link goes in it should be 'safe', all robots shoud be treated as dangerous whatever state they are in. If the robot goes out of control being a spinner then it will not be approached by an arena marshal until the batteries have run out, so it doesn't matter where the link is.