>Would MMP want to print them? Would the majority want to buy them? Until those questions are better answered, the overlays may not see the light. They would be easy enough to do, and I'd even be able to somewhat closely match the various colors and styles of the different geoboards so as to make the overlays blend in well. It's up to MMP.
Send out your thoughts about these board 3, 6, 13, 14, 24 overlays to 10-15 designers (Shelling, Smith, Pitman, Kenney, etc.) and ask them specifically if they have a scenario in the works that could use one of these boards with the overlays you have in mind.
The designers/scenarios are going to drive this project. If you can come up with 12-15 good scenarios that use these overlays then create the Action Pack. Not all the overlays need to be used. For instance, you can have 10 scenarios and 20 board altering overlays. Once these overlays have been published by MMP and are 'officially' released in an AP the other designers are going to use them.