Place roast in a greased 4- or 5-qt. slow cooker. In a large bowl, combine tomato sauce, beer, brown sugar, honey, tomato paste, seasonings and, if desired, liquid smoke; pour over meat. Cook, covered, on low 6-8 hours or until meat is tender., Remove roast. When cool enough to handle, shred meat with two forks. Skim fat from cooking juices. Return meat to slow cooker; heat through., Using tongs, place meat mixture on bun bottoms. Replace tops.