So that optics aren't damaged during assembly, I built an area designated for putting together optics and mounts. The area is covered in teflon to reduce damage if a drop does occur and has a 3D printed PLA ring to keep objects inside the square. Especially for BS cubes, the post should be forked down and the mount should be screwed into the mount. See attached photo.
Attached are the SolidWorks and STL files for the three 3D printed parts for this assembly.