Personally haven’t figured out how to prevent for all situations (e.g. power loss, reset or filament sensor trigger). Have tried to reduce number of conditions that result in freefall via Klipper Macro that moves to safe height after print completes, or before idle timeout powers down the steppers.
Saw MP3DP Repeat V2 (aka V4) z steppers - #6 by kwledbetter, but am not sure if/what config/mechanical solutions others have tried? Personally considered counter weights even…