Add water and liquid smoke to the inner pot. Place steamer rack in the pot. Set aside.
In a small bowl, combine chili powder, salt, pepper, and garlic powder.
Using paper towels, pat chicken dry. Season chicken with the BBQ Rub. Arrange seasoned chicken on steamer rack in the pot.
Close and lock the lid. Cook on High for 8 minutes. When the cooking time is done let the pot stand, covered, 10 minutes. Then turn the steam release handle and remove the lid. An instant-read thermometer inserted in the thickest part of the thigh should register 165°F. If more cooking time is needed, close and lock the lid and cook on High for 2 minutes and then quickly release the pressure. Transfer chicken to a plate and set aside.
Discard all but 1/4 cup liquid from the pot. Stir in ketchup, molasses, onions, Worcestershire sauce, and Dijon mustard. Select Sauté and cook, stirring, 3 to 5 minutes or until sauce is reduced by about one-third. Press Cancel. Stir in vinegar. Season to taste with salt and pepper.
Return chicken and any accumulated juices to the pot. Turn chicken to coat with sauce.
Transfer chicken to serving platter. Serve with additional sauce on the side.