to all the old timers
I'm having trouble trying to figure out the difference between the function of a pin router and a table mounted bit with a bearing on top. Both function with templates. However, you have to remember there is a substantial difference between a pin router and a pneumatic overarm router. The pin router and the bearing work in two dimensions whereas the pneumatic overarm will work, freehand, in three dimensions but not with a template.
I would reason that a template with a bearing on a flush trim bit would be more effective in small numbers, but I have to agree with Gav and others that large numbers would require a CNC machine.
Whatever you decide to work with, you're going to have to develop a process to develop the most proficient production with the highest quality product. That is the part I find most interesting.
Enjoy and keep us posted on your progress and methods.