Sorry, you’re right. For some reason new game projects won’t have it enabled… Not sure why…
You can still enable it by adding:
r.DefaultFeature.AutoExposure.ExtendDefaultLuminanceRange=True
…to your projects DefaultEngine.ini file located in ProjectFolder\Config under the [/Script/Engine.RendererSettings] section:
Obviously, I wouldn’t consider this ideal. The checkbox was more convenient… You may want to consider reporting this as a bug, as I think the whole reason they removed it from the project settings is because it was supposed to be enabled by default…