You can’t define your own voicings and add them to the list, but there are a couple of ways you can work around this.
You could create a progression with the chords and inversions you like. Once you are done, simply save it, this will open it as a “chordset” which you can now transpose up and down to change which scale your progression is in.
It is not exactly what you want to do, but it should get you close enough. You can have many of those “tool sets” ready and recall them when looking for one of your specific voicings.