We eat at this Culver's a lot with my 5 year old daughter who has celiac disease. I always make sure to ask to mark her order as a gluten allergy. They have protocols they follow. GF buns are an option. Culver's corporate has also been helpful in asking questions about specific questions (for example the Ruben, which is GF without the bun).
No issues yet.
GF items are marked online on their allergen menu. GF food USUALLY comes out on its own tray.
— Somewhat
— Gluten-free items are marked on the main menu
— Some
— Excellent