As with many interesting ideas, I think people have come up with better ways to do it...
Modern servo drives use a motor to provide turning power, and a separate encoder to measure position. A typical encoder might have 2500 identifiable positions per revolution, giving much higher resolution than steppers with the benefit of full motor power available at all positions, unlike steppers using micro-steps. And in general, stepper motor shafts are capable of taking any torque that the motor could generate - sufficient to stall the motor, at any rate.
I'm not even sure if the price of steppers these days makes them worth repairing, if you've managed to abuse one to the point that the shaft is damaged. There's probably collateral damage internally!