Clamp on rings using 3mm x 8mm long screws to give a homing reference to z motor position in case one side z is moved out of sync to the other. You set the z bed frames to same distance from top of frame down. Then auto home.The pointer is then aligned to reference line, so you have a way to see if it was moved while stepper motors were un powered.

Creality

Ender 5

No

No

.20

15%

Use a lighter collor filament so you can use paint or black permanet marker to have pointer tip and reference groove stand out visually.