Well, the CinemaScope screens installed in the 1950's only had a slight curve. Smileboxing them would probably do more harm than good.
Really, Smileboxing is absolutely necessary for 3-panel Cinerama because of the wide-angle field. Without it, it's very distorted.
Parts of the first Todd-AO films may have a little benifit, but only the bugeye lens shots (Fogg's first entry to the Reform Club, the bullfighters entering the ring, the shot of the elephant going through brush, the second to last shot of the film, etc). Only 2-3 shots in Oklahoma! would benifit from Smilebox. And most of the Super Panavision or Ultra Panavision films were not made for the intent of an ultra-curved screen like 2001: A Space Odyssey and It's a Mad Mad Mad Mad World (the decision to make the latter in Super Cinerama was made after it was in the can).