Heat pellet grill or smoker to 250℉ with your choice of wood or pellets.
In a large mixing bowl, mix together the egg, milk, ¼ cup barbecue sauce, minced garlic, and 1 tablespoon barbecue seasoning until well combined. Then mix in the crushed pork rinds, grated onion, ground beef, and ground beef/pork/veal blend. Use your hands or a wooden spoon to incorporate all of the ingredients together. Allow the mixture to sit in the refrigerator for about 15 minutes for all of the ingredients to come together and the pork rinds to soak up some of the moisture.
While the meatball mixture is resting, oil a wire cooling rack with non-stick cooking spray or a paper towel with a few drops of cooking oil. Set aside.
Use a cookie scoop or measuring cup to portion out about ¼ cup of the meat mixture, and roll it in the palms of your hands to form a ball. Repeat until all of the meatballs are formed. *You should have 20 meatballs.
Sprinkle the meatballs with the remaining barbecue seasoning, and transfer to the wire cooling rack, evenly spaced.
Place the wire cooling rack with the meatballs on the indirect heat side of the grill. Smoke at 250℉ until the internal temperature of the meatballs reaches about 140-145℉ as read by an instant read meat thermometer. *Our meatballs took about 1 hour to reach 145℉ internal temp, but cooking times will vary based on your pellet grill and the size of your meatballs.
Once the meatballs hit about 145°F internal temp, start basting them with your favorite barbecue sauce. You can use a pastry brush, basting brush, or spoon to glaze the top of each ball. Continue cooking, glazing every 15 minutes, until the meatballs reach an internal temperature of 160°F. *Total smoking time for us was 1 hour and 45 minutes, but cook times will vary.
Transfer smoked barbecue meatballs to a serving platter. Serve warm.