@superhans I’m using an extremely high-tech method , the excess styrofoam packing material from a past shipment. Blocks of varying height to aid in positioning the y-axis while I work on various prototypes…
Yup, the first 3 or so power-offs resulted in the nozzle-nose-dive into the optical mirror I use as the print-bed. Surprisingly, no damage to the mirror and a quick check of the nozzle tip and back in business. Not recommended, two-thumbs down, unless you love to check the alignments of xy and z after each event.
I’m going to design a small device that is powered from a capacitor with just-enough juice to engage a solenoid. A sensor will detect loss-of-power and engage the solenoid using the accumulated power in the capacitor, and when power returns, disengages the solenoid. A short algorithm on a cheap micro-controller will decide the position of the solenoid. A project for another day, although if I fall-into that rabbit-hole maybe sooner