@synchromesh Good news - that method still works, and it looks like Lee has added support for custom Character Creator folders, so that makes things a little easier to keep custom characters separate from stock characters.
Just unzip the attached folder to your Files/charactercreatorplus/parts
folder. Then you'll have a new category called "Mannequin" in the character creator. The head, legs, and feet are "blank" parts like shown in the github link. The body selection contains 5 versions of the Mannequin that you can create characters from and assign behaviors. Check out the folder contents, hopefully it makes sense and you can use this as a template for other custom character categories. Lee had mentioned streamlining this process a bit more in that github link I posted, by making an "import full character" button, but it doesn't look like that has happened just yet.
Here is a video showing the mannequins in the CC and some gameplay: