Hinge-Mate Router Template + Small Hinges?

Has anyone used the Hinge-Mate template to cut mortices for small hinges? I am trying to figure out whether/how it's possible to set up the Hinge-Mate for a small box hinge. There's no problem setting the length or "y" axis of the hinge, or the depth. What I'm having trouble with is a mechanical way to set up the template so it doesn't cut too wide (the "x" axis) a mortice for the narrow-width hinge. The only thing I can think of is to use a spacer behind the work, but the thickness of that space would be trial and error, I think. Any ideas welcome!