To prepare glaze: In a small saucepan, combine ketchup, brown sugar and vinegar, and reserve.
To prepare meatloaf: Preheat oven to 350 degrees and line a rimmed baking sheet with aluminum foil.
In a medium skillet over medium heat, warm the oil. Add the onion and garlic and sauté until softened, about 5 minutes. Remove from heat and reserve.
In a large bowl, combine the eggs, thyme, salt, black pepper, mustard, Worcestershire sauce, hot pepper sauce and milk (or yogurt). Add the meat, crackers, parsley and cooked onion and garlic. Using a fork, mix until evenly blended and the meat mixture does not stick to the bowl (if mixture sticks, add milk, a couple of tablespoons at a time, until the mixture no longer sticks).
Turn the meat mixture out onto a work surface. With wet hands, pat the mixture into a loaf shape, approximately 5 by 9 inches. Place on prepared baking sheet. Brush loaf with half of the glaze, then arrange the bacon slices crosswise over the loaf, overlapping them slightly, to completely cover the surface of the loaf. Use a spatula to tuck the bacon ends beneath the loaf.
Bake the loaf until the bacon is crisp and the internal temperature of the loaf registers 160 degrees, about 1 hour. Remove from oven and cool at least 20 minutes. While meatloaf is cooling, simmer the remaining glaze over medium heat until glaze thickens slightly. Pour glaze into a serving pitcher, slice the meatloaf and serve with remaining glaze passed separately.