Hi Canaan,
You will definitely want some more rock higher up to fill in some of the space and create barriers for both fish and coral. It will also create layers, additional mounting areas and light gradients to accommodate different coral requirements in light and flow.
More importantly, (in my opinion) make sure you’re giving yourself enough space between the rock work and the glass. I always make sure to have at least 4 inches (and it’s never enough) of space along the front and sides or the tank. Imagine having to pick something up from the sand, scrubbing algae, using a net or a fish trap. Coral growth should also be considered. I can’t tell you how many times I’ve “fragged” colonies unintentionally.
Additionally, having more free floor space allows for greater variety when it comes to substrate dwelling fish, inverts, and coral. Have you worked on a stocking list? They often get thrown out of the window later in the journey but thy can help mold your initial aquascape design.
Hopefully that helps. Feel free to reach out if you have any questions.
Thanks,
Mike