On a 40B it can go either way. If made with the same thickness glass as they usually are, you can go brace or no brace. I've seen both. They are only 3 feet long and pretty short so the pressures aren't too bad.
As for the second comment on cutting a brace out of a full 55, not a wise idea. It may be fine, and it may bow the glass eventually causing an issue. 55s are long and tall and the brace is there for a structural reason. But to each their own. Hopefully it holds.