How do we catch the right-looking insert with the wrong recipe?

I brought two housing inserts to our FR10 changeover review and managed to put the wrong one on the drawing while explaining how obvious the difference was. So that went well. They share the same mounting holes. Both can also be turned round, and the recipe screen only asks the operator to confirm the name they've selected. We're considering a mechanical key for orientation, but that still leaves two families fitting the base. Has anyone got a workable way of checking the installed family against the recipe without relying on somebody remembering which tiny pocket is different?