If you like to customize the number of the keystone holes, simply click on customize and change the module_count from 1 to any number ≤ 12.

10-inch patch panel with 12 keystone module space. It's designed and created with OpenSCAD. The standard unit width is 44.45 mm, but to save some space for my very small network rack, I used 30 mm. You can change the module_count variable in the scad file and generate the new stl for it.