There's no real speed benefit for the C-Duino as it only communicates through D+ and D- pins, identical to the pro micro, but I don't like having a cable for every single device on my desk. I designed the PCB on EasyEda, ordered it on JLCPCB, and the components on LCSC. I have not yet tested it on more advanced cables with built in controller boards such as Thunderbolt 3 but basic USB-C to USB-A cables work fine. The GitHub repository with all of the pictures and PCB files is linked below and I hope more people can make this project in order to perfect it in the future. If you have specific questions, feel free to message me and ask. Detailed instructions on construction are coming in the future but for those more advanced, all of the necessary information can be found on the GitHub.