Justafan, you're smarter than I am but have you looked into whether it's practical/possible to open up access to the template layers? What I'm picturing is having the user add template files to the appropriate folder. When the app is started, it reads in the available templates to populate the choices.
So, say I want more side panel choices. Someone creates a file similar to this:
.
I save that in the "sidepanels" folder and the next time I run the jersey creator, I have a new choice of side panels.
Thoughts?