These Multiboard's compatible connectors allow you to use the excellent kliptt cable holders https://www.printables.com/model/424351-klippt-locking-cable-clip with your multiboard. These connectors screw directly into the multiboard small threaded holes.

Do not overtight these bolts. The pressure exerted by doing so will likely snap the head off.

There are kliptt cable holders of different sizes. Bend the klippt a little bit and slide it into the connector. 

This model is not a derivative work of Multiboard files.