An example airfoil vane according to the present disclosure includes an airfoil section including an outer wall that defines an internal cavity, and an insert situated in the internal cavity. A space is defined between the insert and the airfoil outer wall, the insert including an insert wall. A plurality of standoff features extend from the insert wall into the space and contact the airfoil outer wall at a contact area, whereby the standoff features are configured to block airflow in the space at the contact area and redirect the airflow to gaps between the standoff features. A gas turbine engine with the example airfoil vane and a method of assembling an airfoil vane are also disclosed.