I love In N Out. As someone with Celiac, I can't have fries everywhere due to breaded items going into the fryer and contaminating things. The only thing that goes into the fryer here are potatoes. Happy day!
When ordering my protein style burger, I let them know it is an allergy burger and they change gloves and spatulas to ensure no cross contamination. You can't get any spread on your burger because of cross contamination with buns (spread is in a tub, so crumbs get into it), BUT you can get spread on the side in a packet and that is safe. Score.