We have done quite a few Shadow Board projects, all for big companies not individuals. Doing them right takes both a good process, talent, time, and money.
We looked at a lot of methods including shadow boxes, photography, and even 3D imagery. Of course there is the trace and cut with a razor blade mode also but that is generally not pretty and definitely not repeatable. We settled in with a grid system and careful measurements. In every case a fair amount of CAD work was needed along with a bunch of check plots to test and validate both placement and fitment.
The big issue is cost, especially for the average Joe. No matter how you slice it it is a time consuming and expensive task. Other than being OCD or looking cool in the home or small shop there is no compelling need for expensive shadow boards in a home or small business shop.
For applications where FOD (Foreign Object Debris) is of concern, as in aircraft maintenance, DOD applications or high value storage, the cost of the design process and manufacturing are on no concern; shadow boards are a must. Those tool kits are fixed in content and fully managed. We have even gone so far as to laser etch serial numbers in the tools.
Not to sound like doom and gloom but I do not believe there is a big enough individual end-user market to form a business around. In the 1000's of Lista and Vidmar cabinets we have sold I have never had an end user customer who went beyond curiosity with shadow boards. It has always been with a major contractor type.
I think the real shadowboard market lies with jobs that have FOD or high value management requirements not with a Garage Journal type of person.
IMHO
Joe