I guess this all comes down to how shady the area is and the lighting unit you use. Assuming you have enough light in your tank then you could use water flow to help in this situation.
This also happens in nature. In nature, water flow plays an important role in this. If you can have sufficient water flow in your tank, the rippling effect from the water surface would re-direct the light in different directions. The water could also bring food , assist in gas exchange, wash away slime preventing suffocation and ultimately increase the chance for the shaded areas' survival rate. I would not say this would help if part of the coral is in total darkness, OK??
HTH!