Oh I just tried it, but it does not do what I meant.
My issue is that the controller tends to move somewhere else, so at some point it might be quite a distance away from the actual head, floating somewhere off the body.
I believe that happens if you grab parts and move them in play mode.
I think the issue is that you don't get how the system works.
Each node (what you're calling the controller) is attached to its corresponding body part with a spring. So when you drag a node, the body part gets pulled along, too. But it's also held back by all the other springs holding other nodes in place. The more nodes you have turned on, the worse this problem is going to be.
So if you're trying to move, say, the head, and it's barely moving, it can be tempting to just move the node farther and farther away to get it to move. The problem is that this puts the body under tension, making any future movement even harder.
Simply looking at the active nodes and imagining the springs holding them will let you understand what's going on.
Some good practices to help avoid this problem:
1) only have a node turned on if it needs to be turned on. The "control&physics2" tab has buttons for various mass configuration of nodes. These are usefull, especially after loading a pose. Some of those load with all the nodes turned on, which makes it almost impossible to reposition them. "key nodes on" turns off everything but head, hip chest, hands and feet, which makes the model really easy to reposition. For fine tuning position, you may then want to turn other nodes on as needed.
2) Never let a node get too far from its body. If you find yourself having to drag a node far from the body to get the body part to move, stop what you're doing and look at the other nodes. What's holding it back? Better to fix the problem than fight against it. You never want any nodes spring pulled too tight.
3) Turning a node off and on again is a good quick way to put it back in a position where there's zero tension on its spring.
