Heat the oven to 425°F and oil a rimmed sheet. Soak panko in milk for 3 minutes, then gently mix with pork, minced bacon, egg, salt, pepper and sage. Shape 24 equal meatballs.
Bake for 18 to 22 minutes until the centers reach 160°F. Lift meatballs away from the rendered fat with a slotted spatula.
Meanwhile, pour bourbon into a saucepan away from open flame and simmer gently for 4 to 5 minutes. Stir in ketchup, broth, molasses, vinegar and Dijon and bring back to a simmer.
Transfer hot sauce and hot meatballs to a 4-quart slow cooker. Cover and cook on HIGH for 2 hours, turning gently once, until the centers reach 165°F. Uncover for the final 10 to 15 minutes if the glaze needs reducing.
Stir gently to coat and serve about 3 meatballs per appetizer portion. Keep covered on WARM only while the food remains at least 140°F.