[Joel]

You'll likely have to make a new Diagram Style and new Template in combination here:

- Make a new document based on the Chalkboard template
- Change your font size and stroke width (and in this case, the line length in the Diagram Layout Inspector)
- Export this as a Diagram Style
- Make a new document based on the Chalkboard template, again
- Apply the newly saved Diagram Style
- Export this now as a template

Hope that helps,