The shop can only set the bow up to generally used settings. Tuning a bow is done with the owner (you) shooting the bow and making adjustments as necessary for good arrow flight. Arrows with field points/target points can shoot well and group very well even with a bow that is not well tuned. When you put broadheads on (little wings) they can and will show imperfections in the tuning because they windplane if the arrow isn't leaving the bow true.

This is all explained in Easton's Tuning Guide as is how to properly tune for good broadhead flight. You might find the guide on Easton's website or at Hunter's Friend