finally a climate-neutral possibility to mine bitcoin

That's ridiculous.
Cat-bread's have almost no torque.
I'm more concerned about the labor involved fixing the crankshaft to that particular attach point. I imagine claw proof protective gear is in order.
You should always add a spring between the cat and the bread. (aka an rpm governor)
When the cat rotates too fast the centrifugal force pushes the bread farther away from the cat reducing the speed.
