Heat the olive oil in a skillet over medium heat. Add the chopped mushrooms and cook for 6 to 8 minutes, stirring often, until their moisture has cooked off and they are lightly browned. Set aside to cool.
In a large mixing bowl, combine the ground beef, egg, breadcrumbs, Swiss cheese, onion, garlic powder, salt, pepper, and cooled mushrooms. Mix gently until just combined. Avoid compacting the mixture.
Shape the mixture into a loaf and place it on a rimmed sheet pan or in a smoker-safe loaf pan.
Preheat the smoker to 250°F. Add the meatloaf and smoke until the center reaches 150°F, about 1½ to 2 hours. Cooking time can vary, so use a meat thermometer.
While the meatloaf smokes, stir together the BBQ sauce, cooled coffee, and Worcestershire sauce in a small bowl.
Brush the glaze over the meatloaf when its center reaches 150°F. Continue smoking until the center reaches 160°F.
Remove the meatloaf from the smoker and let it rest for 10 minutes before slicing.