I have a Wolfcraft workbench i needed to cover the holes so i designed a customizable stop/cover for this holes using OpenSCAD.

If you have other brand or model you can change values as you need. I have added some screenshots displaying changes in parameters.

The STL file attached is what i printed.

Repository:
https://gitlab.com/joaquinfq/openscad/blob/master/Tools/WolfcraftStops.scad

Anet

A8

Doesn't Matter

Doesn't Matter

0.4