The shank rides on the edge of the pattern (template). The cutting part of the bit rides in the guitar top's f-hole to be. Burning of the pattern (template)is minimal and no distortion of the template should occur.
As always, it is critical to be sure that the router bit is secure and the shank rides exactly where it needs to be. And the cutting portion does not cut the template.
Careful checking and testing on scrap is required.