Wallace was terrific. I thought I would see much more of him, but that was not to be. I remember he had a small role, along with some other Chicago actors, in the Steven Segal Film Above the Law, which was set in and shot in Chicago. The Internet Movie Database shows that Wallace has been in many TV shows and movies (link), and I’m glad for him for that; it has just one photo of him, though -- as part of a cast group picture from the movie Boogie Nights. A great performance in Cuckoo’s Nest I still remember, these many years later.
(The nearby image I pulled off a Google search.)