For MP3DP or similar printers (perhaps the voron trident) that use 3 belted motors that can auto tilt level and hold up the z bed for a core-xy printer, there have been reports that upon power loss, the dropping of the bed can cause sufficient back EMF from the stepper to blow motor drivers or control board regulators.  I made a circuit that effectively works as an auto-belay for the motor movement to slow the bed descent when conditions allow.  This model is the outline and holes of that board so users can make a mount for it to whatever electrical setup is desired.