In large bowl, mix together ground beef, breadcrumbs, ¼ cup (60 mL) barbecue sauce and egg. Shape into loaf and place on soaked plank.
Place planked meat loaf on grill preheated to high heat. Close lid and cook 25 min., brushing meat loaf with remaining barbecue sauce about every 10 min., until a meat thermometer registers 160°F (71°C) and meatloaf turns golden around edges. Remove from grill; rest 10 min. before slicing.
Meanwhile, place kale in microwaveable bowl with 2 tbsp (30 mL) water. Microwave on HIGH until kale is softened, 2 to 3 min.; drain well.
In large bowl, whisk together olive oil, vinegar and salt. Add kale, corn and cheese; toss to combine. Serve with sliced meat loaf.