Except that won’t help with situations where the mcu is confused as to where the bed/toolhead is, such as if a homing sensor fails, or if your steps/mm (or esteps) are wrong, or if you’re going the wrong way because you plugged in a cable the wrong way, or any of a million other cases where it can fail in a non-skipping way.
But yes, closed loop is obviously the way to go, in addition to safety stops. That way you could even have a smart driver that can adjust the current dynamically. (Well, actually the most preferred would be absolute encoding, so that you wouldn’t need homing, because all moving parts’ locations can be read immediately when turning on the device. I haven’t seen any decent absolute encoders, though. One would think it shouldn’t be that hard, considering there are pretty damn accurate digital calipers that cost practically nothing.)
Hello, I have a bit different solution for protection durning homing/start print moves. I’m using current change macro for the motors:
[gcode_macro STANDARD_CURRENT_MODE]
description: Set steppers current to ready to print values
gcode:
SET_TMC_CURRENT STEPPER=stepper_a CURRENT=1.25 HOLDCURRENT=0.50
SET_TMC_CURRENT STEPPER=stepper_b CURRENT=1.25 HOLDCURRENT=0.50
SET_TMC_CURRENT STEPPER=stepper_c CURRENT=1.25 HOLDCURRENT=0.50
[gcode_macro LOW_CURRENT_MODE]
description: Set steppers current to low values to avoid damage
gcode:
SET_TMC_CURRENT STEPPER=stepper_a CURRENT=0.4 HOLDCURRENT=0.3
SET_TMC_CURRENT STEPPER=stepper_b CURRENT=0.4 HOLDCURRENT=0.3
SET_TMC_CURRENT STEPPER=stepper_c CURRENT=0.4 HOLDCURRENT=0.3
In start_print gcode/macro use low current mode, slowly drivre to prime line start positions (0.1mm above) and then change to standard current. It’s saving hotends and i think it also can be used in sensorless homing.
It’s not answer for your main question but it can solve some issues without any external HW.