Ok, here is a holder for Eurorack patch cables that is somewhat parametric. I am new to sharing stuff on thingiverse so hopefully this works as I assume it should. I have included the Fusion3D file, where you can change parameters for arm spacing, arm width, arm quantity and a few other things. Some values such as setting the arm width too low will make the model wonky, but after testing a few values on quantity and spacing it seems to work well enough. If there is something I need to change or improve don't hesitate to tell me, I am quite new to parametric modelling so I am sure I have made some mistakes :)
The STL I have included has a 4mm spacing between arms. Rotate the print 90 degree so that the arms are flat on the print surface for maximum strength.
You will probably get away with not printing supports for the screw holes if your printer is well calibrated.