Up until about a year ago I used to fit the LED in routed grooves in a plastic front panel, to shade each row of LEDs.
It was fiddly and expensive to do, and if the board was pointed towards the North East the sun still got to the LEDs in late afternoon ( we are in the Southern hemisphere )
( I love it when they ask for a southern facing board so it is always shaded )
Now the LEDs are so bright that shading is not needed, but it still needs a double row :-
And you have problems with powering and heat.
These are leant back looking straight into the sun so not shaded by the grooves, and are perfectly clear.
The latest ones are even better, and for evening sport the auto dimming I have had to fit turns them right down to less than 10% duty cycle.
One of the problems is that schools and clubs want the scoreboard across the field from the clubhouse, often where there is no power.
Sinking cable around the field is very expensive, and could kill the sale, so if I can get affordable solar panels ( and deep cycle battery ) it might swing some sales.
The shop I worked at made the "Odds Windows" for the Delaware Race Track (horse races, long field, big stands, etc) IIRC in 1980 or 81. Every set of lights to make 1 digit/character set at the bottom of an open front box perhaps 20 cm deep. The box grid was made of 1/2 mm aluminum strips with slits that horizontal and vertical interlocked. Using aluminum strips to go in a steel frame was probably not a great idea (dissimilar metals, eventual corrosion) but it worked well.
You could try just for your own look-at, find a cardboard box big enough and set digits inside with the front open and see what that does to your power requirements. Less would help, wouldn't it?
I don't know about Africa but here the sun is not so bright when it's low in the sky.