A fix to the HDR documentation page: High Dynamic Range Display Output | Unreal Engine Documentation
Following this page’s recommendation to use the “Enable HDR Display Output” will never work in a standard project. The docs fail to mention that the source checks whether the config variable “r.AllowHDR” is set to 1 or not, otherwise it ignores the request. Using the console command bypasses this check but also bypasses the automatic setting of fullscreen modes so is less useful.
The “r.AllowHDR” config variable should really be mentioned on this page, you’ll only find out about it by reading the source code otherwise.