Tentacle management is coming along nicely:
Now if I can just find some way to get the IK solver for the tentacles to stop switching back and forth between two very different solutions for slight variations in the target position...
This can be done with a "look at" invisible bone, you often see them in leg rigging to prevent them from bending backwards at the kneecap. I haven't touched Unity's rigging systems in many years, so I'm not sure how it's done there specifically.
Your controls are coming along nicely, the transitions look pretty smooth.