737
If you care to look at Table 6.1, above the piece you quote in CAP168, you will see what lights are required in differing weather conditions. Strictly, this is what is required to meet licensing requirements, but it follows that is what is displayed in those conditions. You quote says that high intensity systems, where installed, are to be displayed in less than 5km and/or 700ft. And they are. Throwing money at something (leaving all the lights on all of the time - using more electricity, reduced lamp life) does not necessarily make something safer. Someone would have done a hazard analysis on all this.