Well, the search for information on shorthand is rather frustrating. There seems to be a very large gap in history between the Tironian Notes and Timothy Bright's publication.
Again, simply to avoid misconceptions, I do not believe the Voynich to be written in shorthand. I believe the script to have its foundations in shorthand notes, giving it its appearance. The origins of the script are not necessarily a key to the VMS, but are important in its history.