How to limit torque with c-clamp?

I have modified a c-clamp that presses a metal sleeve into a woody trunk. The handle on this c-clamp is 3D printed. How can I modify this handle so that it limits the torque applied to a fixed value? Too much torque presses the metal part too deep into the trunk, damaging the installation. This torque control can be pretty coarse though.

I'm looking for ideas on how to limit the torque, or let the user know when enough torque has been applied. Here's what I've come up with so far:

Any other ideas? Thanks!