Preheat oven to 375°. Place a roasting rack in a roasting pan.
In a medium saucepan, bring orange juice, brown sugar, 4 tablespoons butter, cane syrup, honey, and 1/2 teaspoon salt to a boil over medium-high heat. Reduce heat, and simmer until thickened, about 20 minutes.
In a small sauté pan, heat onion, orange zest, chopped herbs, chipotle, paprika, cayenne, and remaining 1 tablespoon butter over medium heat. Cook until fragrant, about 3 minutes; stir into glaze. Reserve half of the glaze for basting.
Rinse duck, and pat dry with paper towels. Place duck, breast side up, on prepared rack. In a small bowl, whisk together oil, pepper, and remaining 1/2 teaspoon salt. Brush duck with oil mixture. Stuff duck with herb sprigs.
Bake for 20 minutes. Brush duck with some of the basting glaze, and bake until a meat thermometer inserted in thickest portion of breast registers 165°, about 40 minutes more, brushing duck with remaining basting glaze halfway through. Remove from oven. Rewarm glaze in saucepan. Serve with duck. Garnish with orange slices, sage, and tarragon.